I^ATU RAL . HlSTQRY Object Lessons. Ricks. LIBRARY ANNEX 2 :a D.C. Heath 8c Co. Boston njnjojijnjxrunjiJTJTjnjiJi-r (fimndl Winivm^ Jibt^arg THE GIFT OF FcvAYwVvx S>^ /S). ^. \Xil v\VvOL,Y>fVS. \.\^c^^q^«) Q>V\\« CO ALBEhT R. MANN, LIBRARY AT CCR?^ELL UNIVERSITY Cornell University Library QH 53.R53 1891 Natural history object lessons :a manual 3 1924 002 772 618 The original of tliis book is in tlie Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924002772618 NATUEAL HISTOEY OBJECT LESSONS NATURAL HISTORY OBJECT LESSONS a ilttanual for ©eacfters By GEORGE RICKS B.Sc. (lond.) INSPECTOR OF SCHOOLS — SCHOOL BOARD FOR LONDON Part I.— PLANTS AND THEIR PRODUCTS ANIMALS AJSTD THEIR USES Part II. — SPFX'IMEN LESSONS BOSTON, U.S.A. D. C HEATH & CO., PUBLISHERS 1891 PEEFACE. In " Object Lessons, and How to Give Them," First and Second Series, we confined ourselves almost exclusively to the Inorganic World. In this volume, we propose to turn our attention to the Organic World. Plants and animals present an inexhaustible supply of subjects for "Object Lessons ; " but the majority of teachers lack the time and opportunity to search out, gather, and arrange the suitable materials from so vast a treasury. The object of this book is two-fold : (I.) To supply infor- mation from which the teacher, with the least effort, may prepare systematic courses of interesting and instructive " Natural History Lessons," suitable for Public Elementary Schools. (II.) To provide a sufficient number of specimen lessons (a) for the use of young teachers, and (6) to serve as guides in the preparation and construction of other lessons. But in addition to this, a very general sketch of the Vegetable and Animal Kingdoms is given ; sufficient to show to the teacher, not previously conversant with the subject, the general relations of the various groups of plants and animals to each other and to the whole, without which the more advanced lessons, at least, would lose much of their point and force. The book must not be considered, however, in any sense a text-book either of Botany, or Zoology. For a more systematic review of plants the teacher is referred to a little book,* ad- mirable as it is simple, written by V. Murche ; and for a more comprehensive survey of the various groups of animals to the strikingly interesting series of " Natural History Readers " by J. G. Wood, M.A.t • '-Botany as a 'Specific' Subject." Blackie& Son. t London: Isbisters, 6 PREFACE. Properly presented, no lessons are so interesting and attractive to children as those which deal with living plants and animals ; and none are more effective in the cultivation of habits of exact observation, accurate comparison, and sound reasoning. Some little trouble and forethought on the part of the teacher are necessary in the selection and preparation of materials. In the case of plants, wherever possible, complete speci- mens, viz. with roots, stems, leaves, and flowers, should be brought before the class. Hence, in arranging the course of lessons regard must be had to the season of the year when particular plants can be obtained. There is often, too, an appropriateness in fitting the lesson to the season. A lesson on leaf -buds is most appropriate in spring ; a lesson on the wheat-plant, or on fruits, is more suitable for the autumn. As with plants, so with animals, wherever possible, take the living specimen in preference to the picture. It is of course not easy to bring many living animals into the school- room ; but some at least may be introduced, and these will serve as types with which other and similar, but less familiar, animals may be compared. Advantage should be taken of any pet animals which the children may happen to possess, such as white mice, rabbits, squirrel, hedgehog, &c. Besides these it will not be difficult to secure living specimens of birds, fish, frogs, and toads, the common ringed- snakes, insects, earthworms, snails, and so on. Some of these will serve to teach the children that many animals, commonly looked upon as unpleasant, unwholesome, or dangerous, on closer acquaintance prove to be harmless, interesting, and useful. Stuffed specimens of less familiar animals may be used with great advantage. Of course the teacher will endeavour in his mode of dealing with living animals, as well as by precept in his lessons, to cultivate in his scholars a spirit of gentleness and kindly feeling towards all God's creatures weaker and more help- less than themselves. CONTENTS. PART I. PLANTS AND THEIR PEODUOTS. SjEctton E.— f lants. OHAFTSB PAGE I. — INTRODUCTION ... 13 II. — A TTPICAL PLANT I5 III. — GENERAL CLASSIFICATION OF PLANTS 19 IV. MINUTE STRUCTURE OP PLANTS ....... 22 V. — ROOTS AND THEIR FUNCTIONS ....... 25 VI. — STEMS AND THEIR USES ••...... 27 VH. — LEAVES AND BUDS •••....,. 34 VIII. —FLOWERS, THEIR PARPS AND USKS 39 IX. — FRUITS AND SEEDS ......... 44 S)«ttou 11.— tBconomt'c ^totructs of plants. X. — THE PALM-TREES 51 XI. — 0RASSE8 — CEREALS, THE SUGAR-CANE, ETC. .... 55 XII. STARCHES g2 XIII. — OILS AND PATS .60 XIV. — GUMS* RESINS, GUM-KESINS, ETC. ...... 72 XV. — COTTON, HEMP, FLAX, JUTE 78 XVI. — PAPER 85 XVII. — BLEACHING AND DYEING gg XVIII. — TEA, COFFEE, AND CHOCOLATE 92 XIX. — SPICES 98 XX. — OPIUM, aUININE, AND CAMPHOR 100 XXI. — MISCELLANEOUS ARTIOLE.S — INDIGO, OAK-GALLS, ETC. . . . 105 CONTENTS. ANIMALS AND THEIR USES. CHAPTER XXII.— CLASSinCATION OF ANIMALS . . . XXIII. — CLASSIFICATION OP VEaTEBRATA. I. . XXIV. — CLASSIFICATION OF VERTEBUATA. II. XXV. — CLASSIFICATION OP INVEBTEBRATA . XXVI. — COVERINGS OF VERTEBRATE ANIMALS XXVII. — THE BONY SKELETON AND ITS MODIFICATIONS XXVIII. — TEETH — THEIR VARIETIES AND USES XXIX.— TONGUES XXX. — TAILS AND THEIR USES .... XXXI. — THE POSITION AND FUNCTION OF THE PRINCIPAL INTERNAL ORGANS OP ANIMALS PAGE 115 118 123 126 130 139 162 161 166 170 PAET II. SPECIMEN LESSONS. LESSON I. — PAWS AND CLAWS . 180 II. — COCOA-NUT 180 III. COTTON AND WOOL . . . . . . , . .181 IV. — AN EGG 182 V. — ACORN AND HAZEL-NUT 183 VI. — MILK 184 VII. — ONION, TURNIP, CARROT 184 VIII. — CAT AND DOG „ . . 185 IX. — DOWN 186 X. — A aUILL FEATHER 188 XI. — GUTTA-PERCHA 189 XII. — LEAVES 190 XIII. — STARCH. 1 1"J2 XrV. — STARCH. n 193 XV. — STARCH, in. .......... 194 CONTENTS. 9 LESSON FAOB XVI. — THE HOKSB 196 XTII. — THE COW AND THE BHEEP 198 XTIII. — HONEY AND WAX 199 XIX. IVOB.T 201 XX. — SEEDS AND SEEDLINGS. 1 203 XXI. — SEEDS AND SEEDLINGS. II 204 XXII. OLITE OIL 206 XXIII. — LIBEK 208 XXIV. — KINDS OP ANIMALS — (l.) MAMMALS AND BIRDS . . . 209 XXV. KINDS OF ANIMALS — (ll.) REPTILES AND PISHES . . .212 XXVI. — KINDS OP ANIMALS — (ill.) MAMMALS 214 XXVII. CHEWING THE ODD 216 XXVllI. — HORNS AND THEIR USES 219 XXIX.— PARTS OP A FLOWER 221 xxx.^ — birds' nests 223 XXXI. THE HEDGEHOG 226 XXXII. — WHALE-OILS 228 XXXIII.— LEATHER . . • 231 XXXIV.— THE MOLE 234 XXXV. — COTTON 238 XXXVI. — KINDS OF ANIMALS — (iV.) VERTEERATA AND INVEKTEBRATA . 240 XXXVII.- — THE COCKROACH 243 XXXVni. — EARTHWORM 246 XXXIX. — spiders' THREADS 248 XL. BLEACHING . ■ 2fi2 XLI. — THE BAT AND HIS RELATIVES 254 XLII.— BEAKS OP BIRDS 267 XLIII. — SNAKES. 1 269 XLIV. SNAKES. II. 262 XLV. — PISHES. 1 265 XLVi. — PISHES. II 268 XLVII. — INSECTS — (l.) GENERAL FORM AND STRUCTURE . . . 271 XLVIII. — INSECTS — (lI.) CHIEF KINDS. BENEFITS AND INJURIES . . 274 XLIX. — INSECTS — (ill.) METAMORPHOSIS 277 L. — INSECTS — (iV.) LEGS AND FEET 280 LI. — INSECT AND SPIDER 282 LII. — LEGS AND FEET — (l.) MAMMALS 284 tni. — LEGS AND FEET — (ll.) MAMMALS 286 10 CONTENTS. LEBSON PAGE LIT. — LE8B AND FEET — (lH.) MAMMALS 288 LV. — LEGS AND FEET — (l.) BIKDS 290 LVI. — LESS AND FEET — (ll.) BIKDS 292 LVII. — PLOUK 294 LVIII. — THE FKOQ I. . • 297 LIX. — THE FROG — (ll.) LIFE HISTORY ...••• 300 LX. — EGGS. I. ........•• 302 LXI. — EGGS. n 305 LXII. — SNAILS. I. ......... • 308 LXIII. — SNAILS — (ll.) WHELK AND PERIWINKLE 311 LXIV. — SNAILS — (ill.) GARDEN SNAIL, SLUG, AND POND SNAIL . . 313 LXV. — FIRST FORMS OF ANIMAL LIFE — (l.) THE AMCEBA AND FORA- MINIFEKA . 316 LXVI. — FIRST FOEMS OF ANIMAL LIFE— (ll.) THE HYDRA . . 320 LXVII. — FIRST FORMS OF ANIMAL LIFE — (ill.) SEA ANEMONES AND CORALS 323 LXVIII. — PLANT FACTOBIES 327 APPENDIX. SPECIMEN OUTLINE DRAWINGS FOR THE BLACKBOARD. STOMACH OF COW 335 PERCH ............. 837 SLUG 339 INSECT, SHOWING PARTS 341 SPIDER AND WEB, ETC 343 WINQS OF DRAGON-FLY 345 HYDRA TUBNINQ SUMMERSAULTS ........ 347 INDEX 349 PAKT I. PLANTS AND THEIE PEODUCTS ; ANIMALS AND THEIE USES. PLANTS AND THEIR PRODUCTS. CHAPTER I. INTRODUCTION. The earth is clothed with vegetation. From the burning sands and sweltering, humid valleys of the tropics to the confines of the eternal snows, plants, seemingly interminable in number and variety, luxuriate. Each country, each changing degree of temperature, has its particular plants. " The dynasty of the palms," says Linnaeus, " reigns in the warm regions of the globe ; the tropical zones are inhabited by whole races of trees and shrubs ; a rich crown of plants adorns the plains of southern Europe ; troops of green grasses occupy Holland and Denmark ; numerous tribes of mosses are settled in Sweden ; while the white and grey lichens alone vegetate in cold and frozen Lapland." We may even recognise a country by the predominance of certain forms of vegetation. Forests of firs and pines transport us at once to northern latitudes, or to the flanks of high mountain ranges ; forests of gum-trees and acacia tell us of Australia ; the heaths point to South Africa ; and the cactus to Mexico. Not only do plants cover the earth, but they invade the sea ; and, in prodigious numbers, draw their sustenance from the waterv element which surrounds them. The " Gulf- weed" forms floating meadows in the ocean. " Midway in 14 NATDEAL HISTORY OBJECT LESSONS. the Atlantic is the great Sargasso* Sea, covering an area equal in extent to the Mississippi valley ; it is so thiokly matted with the Gulf-weed that the speed of vessels passing through it is often retarded. When the companions of Columbus SAW it, thej^ thought it marked the limits of navigation, and became alarmed. To the eye, at a little distance, it seems substantial enough to walk upon." f Not only has each country and each sea its particular vege- tation, but each tribe of plants requires its own peculiar con- ditions to bring it to perfection. Some revel in the scorching sunshine, others — like the red snow plant — flourish only on the frozen snow ; some luxuriate in moisture, others prefer the parching drought ; sunshine is the life of some, to others it brings death and decay ; to some salt is necessary, and they find a habitation near the sea, on others salt acts as a destroyer ; some prefer to flaunt their broad leaves on the surface of the water, others, more retiring, seek the shel- tered nooks beneath. Some plants lack the power of adapting themselves to slight changes in these conditions, and hence must always be restricted to certain localities : thus the cocoanut-palm grows only in lowlands near the sea ; some on the other hand — like the potato — are more accommodating, and adapt themselves to a great variety of circumstances. Plants make the earth beautiful ; but they also serve a more useful purpose. We could not live without plants — they serve, directly or indirectly, as food for every living animal. Their special work is to change inorganic into organic matter.* They only are endowed with the inscrut- able power of transforming air and water and earth into living matter, and of working them up into an infinite variety of beautiful and useful forms. • Sargassum is the botanical name for the different species of Gulf-weed. t Mnury, ** Physical Geography of the Sea." J Matter oi ganized or arranged to perform special functions. PLANTS AND THEIR PRODUCTS. 15 Leaves of every form, flowers of every hue, the gnarled trunk, the fleshy root, hard nuts, succulent fruits, the sugar of the orange, the acid of the lemon, the starch of the potato, the oil of the olive, poisonous juices and refreshing beverages, are all elaborated from sap; and this sap is made from water, the carbonic acid gas of the air, and a little earthy matter. And, in the very act of making vegetable matter, plants fulfil another great purpose of their existence, viz., they re- move from the air a noxious gas, which, if left to accumulate, would be detrimental to the health of animals. The air we breathe is a mixture of two gases, oxygen and nitrogen, with some aqueous vapour, and traces of carbonic acid gas. Oxygen, which makes up about one-fifth of the air, is the supporter of life — we could not live without it. Now, as we breathe, we change a little of this oxygen into carbonic acid gas. The change takes place within the body, in every part, by the union of the oxygen carried by the blood with carbon from waste tissues. Now this gas is unfit for the breathing of animals — so much so that if it existed in quantity in the air they would be suflbcated. But it is the chief food of plants. They constantly take it from the air, decompose it in their leaves ; and, retaining the carbon, return the oxygen pure, to form the breath of life for animals once more. CHAPTER H, A TYPICAL PLANT. All the common plants of our gardens, and fields, and hedge- rows, consist of roots, stems, and leaves. At certain seasons these plants produce flowers, which in their turn yield fruits and seeds. The roots, stems, and leaves, being more imme- 16 NATURAL HISTORY OBJECT LESSONS. diately concerned in the growth or vegetation of the plant, are called organs of vegetation. The flowers take no share in nourishing the plaat ; their special work is to prepare the seeds from which new phints will grow. They provide for the growth of new individuals of the same species ; in other words, they reproduce and perpetuate the species. Hence flowers are called organs of reproduction. I. The Org-ans of Vegetation. 1. The Root is the part of the plant which descends into the ground, sending its branches in all directions through the soil for the purpose of finding food for the plant. Real roots have neither pith nor true bark, and they never bear leaves. '2. The Stem is the ascending portion which bears the leaves and flowers. The leaves appear at intervals either singly, or in pairs, or in clusters, or whorls. 3. The Leaves usually consist of a flat expanded portion which we call the blade, and the leaf-stalk. Leaves take in the larger portion of the plant's food from the air, and digest both this and that absorbed by the roots. II. The Organs of Reproduction. A flower, with all its parts present, consists of two flower cups. The outside one, usually green, is called the Calyx ; the inner, usuallj' coloured, is called the Corolla ; and within these cups are the Stamens and Pistils. The flower cups serve for the protection of the stamens and pistils when in the bud. They are sometimes called, by virtue of their oifice, %\ie floral envelopes. The stamens and pistils are the essential organs of the flower, because both are essential to the formation of seed. The stamens consist of a number of thread;-like stalks, each bearing a sac called the Anther, The Anthers are filled with a powdery-looking matter called Pollen. PLAKTS AND THEIR PRODUCIS. 17 STIGMA . r'ANTHERS: STAMENS. STYLE. PETAL. PISTIL. FIBRILS. Fig. 2.— Section of Flower. Fig. 1.— A 'L'ypical Plant. 18 NATURAL HISTORY OBJECT LESSONS. The jiistil forms the centre of the flower. It consists of three parts, the Ovaky, or seed vessel at the bottom, con- taining the ovules or young seeds ; the Style, or stalk ; and a rounded or flattened head called the Stigma. These are all the parts which any flower has ; but many flowers have not all these parts. Some have a single in- stead of a double floral envelope, others possess neither ; some stamens have no slender stalk, and some pistils have no style. The necessary parts — the anthers, the ovary, and stigma — are always present, though not in every case on the same plant. Pig. 3.— The Bean, r, radicle ; c, cotyledon ; p, plumule. The Fruit is really the ripened ovary, and the ripened ovules are called Seeds. The seeds consist of a kernel and its shell. Place a pea in water, and soon its softened shell or skin can be easily removed. The kernel is a miniature plant, living, but sleeping till called into active growth by warmth and moisture. Botanists call the miniature plant in the seed the germ, or embryo. The kernel of the seed may consist of an embryo only, as in the bean or pea ; or it may consist of an embryo with a store of PLANTS AND THEIR PRODUCTS. 19 albumen outside, as in the seed of wheat. The white mealy mass, which we call flour, is the albumen of the cereals. In all seeds the embryo consists of three parts, the radicle, plumule, and cotyledons. The radicle is the tiny stemlet from which the root grows, the plumule is the young bud, and the cotyledons are seed-leaves. Some seeds have one seed- leaf, others have two, and a few possess more than two. The cotyledons of the bean are large, fleshy lobes, full of albumen. The albumen stored up in the seed, whether outside the embryo, or in the seed-leaves, serves as food for the young plant. CHAPTER III. GENERAL CLASSIFICATION OF PLANTS. There are so many thousands of different kinds of plants scattered over the globe that it would be impossible for any individual person to study the special characters of each kind. Hence it becomes necessary to present them in orderly array, grouping together those which are most alike, and separating those which are most unlike. A knowledge of the structure and properties of one plant in a group will give us an insight into the character of the other members of the group. Nearly all plants produce flowers ; but the most super- ficial observer must have noticed that some plants — such as ferns, mosses, and lichens, are flowerless. Here, then, we have the first natural subdivision of all plants into two sub- kingdoms — the Flowering Plants, and the Flowerless Plants. We saw in the last chapter that some seeds have two 20 NATURAL HISTORY OBJECT LESSONS. seed-leaves or cotyledons, while others have only one seed- leaf or cotyledon. This difference in the embryo is accom- panied by other differences in the fuU-grown plant, which together serve to divide the flowering plants into two great classes, the Dicotyledonous and Monocotyledonous plants. For instance, the stem of a Dicotyledonous* plant has a distinct bark, and the wood is arranged in concentric layers round the central pith. Each year a new layer of wood is formed on the surface of that formed in the previous year. The leaves of this great class have their veins arranged in a kind of network, and the parts of the flowers in fives or fours, or multiples of these numbers, and very rarely in threes. The stem of a monocotyledonous plant has no distinct bark which can be peeled clean off the wood, and the wood is arranged in threads which are mixed up with the pith through- out the stem. The veins of the leaves run in a nearly straight direction from the leaf-stalk to the point, and are almost parallel to each other. The parts of the flower are arranged in threes, or a multiple of three — very rarely in twos or fours, and never in fives. Thus the class of any flowering plant may be discovered from an examination of a seed, or a piece of its stem ; and it may be from a single leaf, or blossom. Many seeds are very minute, and it is not possible to examine their structure without the aid of a microscope ; nor can we always find seeds in a growing state. The structure of the stem is a guide quite as certain, and much more obvious to the naked eye than the structure of the seed. Hence it is more common to name the two great classes of flowering plants after the method of growth in the stem. In the first class, as we have seen, the stem increases by the addition of woody fibre on the outside of the woody * The pine-trees and plants like them, which have more than two seed- leaves, are included in this class. PLANTS AND THEIR PRODUCTS. 21 fibre previously formed. Such plants are named Exogens, or OM^warc?-growers. In the second class the bundles of woody fibre are deposited towards the centre of the stem, and these push out those preyiously formed and thus increase the diameter. Such plants are named Endogens, or inward- growers. The Dicotyledonous, or Exogenous class includes the vast majority of plants in all parts of the globe. Nearly all the common herbs and shrubs and trees of this and other temperate countries are Exogenous. The Monocotyledonous, or Endogenous plants are represented in this country by the Cereals and other Grasses, the Lilies, the Onion, and a iew others. The Monocotyledonous, or Endoge- nous, class are more characteristic of tropical regions, where they are found side by side with Exogenous plants. The Palms, Screw-pines, Bamboos, and Canes are the most striking examples. The Flowerless Plants bear no real flower with anthers and pistil, and so can- \M«f not produce real seeds. They produce, however, simple minute bodies, which '^CTZ^At^'^- answer the purpose of seeds. These are •' ^v7\! v called SBores. Spores may usually be seen Fig- 4. — Fern - ■1 , if J a £ i.\. leaves, showing m plenty on the under suriace oi the Spores. leaves of the Fern-tribe. Ferns, Mosses, Lichens, Fungi, and Sea- weeds are all Flowerless plants reproduced by spores. These plants are usually arranged in two divisions. The first includes the Ferns and Mosses, whose stems grow by the addition at the summit. Such plants are called Acrogens, or smnmit- growers. 22 NATURAL HISTORY OBJECT LESSONS. The Lichens, Fungi, and Sea-weeds have neither distinct stem nor leaves ; they consist of expansions of simple sacs, or cells. They are named Thallogens.* Fig. 5. — Thallogen (Iceland Lichen). CHAPTER IV. MINUTE STRUCTURE OF PLANTS. Plants in their most simple forms are built up of vast numbers of microscopic lags, or sacs, or bladders, united toge- ther in various ways. These sacs are called cells, and the tissue formed by them is called Cellular Tissue. Cellular tissue plays the main part in the life-history of every plant which grows, and it is the chief fabric of which every plant is composed. The lowest tribes of plants, such as sea-weeds, lichens, mosses and mushrooms, consist of little else besides cellular tissue. In fact, they are often called cellular plants. The young plant, too, even of the * Thallos, green shoot ; and genos, hirth. PLANTS AND THEIR PRODUCTS. 23 ITigs. 6 and 7.— Cellular Plants magnified. highest tribes, consists entirely of this kind of structure ; and in all newly-forming parts the foundation, as it were, is laid with cells. In the mature plant cellular tissue abounds in leaves, flowers, bark, pith, fleshy fruits, and succulent roots and stems. If we take a young succulent leaf, and remove a piece of the delicate skin from the upper part of the leaf, we may see by the help of a pocket lens a vast number of green more or less rounded cells * closely packed together. This is the cellular tissue of the leaf. The cells which form cellular tissue- vary very much in shape and size, and various changes take place in them dur- ing the growth of the plant. It will not be necessary for our present purpose, however, to consider all these. But there are certain which are long and narrow and spindle - shaped from the first, to which we must refer. These serve a very important purpose. Each hair, for instance, of the "wool" which covers the seed of the cotton plant, is a single long cell. Flax, hemp, and jute are composed of simi- lar long cells. All these cells when young have soft elastic walls, and their contents are semi-fluid, so that, in order that a soft young seedling may become a stout tree, the cells must become hardened * For a closer examination of these cells a microscope is necessary. S.— Cellular Tissue. cells, '^f^. ^ Fig. 9.- -Cotton Seed and Hairs. 24 NATURAL HISTORY OBJECT LESSONS. in some way or other. This is effected by the deposit of a substance of a woody nature, formed from the half-fluid contents, on the inside of the cell-wall. In time, the walls become so thick that the cell is almost choked up. After this it undergoes no further change, and may be considered as practically dead. The hard shell of the cocoa-nut, the stone of the cherry, peach, and plum, and the " ivory " of the seed of the ivory-palm, are all formed from hardened short cells. Tissue formed from the hard tough long cells is called Woody Tissue. The woody portion of trees, and shrubs and herbs, and indeed of all flowering plants, consists in part of this tissue. It exists also in the inner bark of When separated from raw material for Fig. 10.— Woody Tissue, magnified. trees, and in the veins of leaves. the more delicate tissues it forms the many textile manufactures, and is known under the general name of hast, or liber. Mixed up with the cellular and woody tissue, we find other tissue consisting of tubes. These appear to be formed from rows of cells, which have grown firmly together, and from which the partition walls have disappeared. Hollow tubes so formed are called vessels, and the tissue is named Vascular Tissue. Sometimes these vessels contain a fine thread coiled round and round in a sort of spiral. This spiral fibre may easily be seen by making a superficial cut round the leaf-stalk of a strawberry or geranium, and then pulling the parts gently asunder. The uncoiled fibre looks like a spider's web. All the parts of plants — roots, stems, leaves, flowers, fruits — are made up of cells and vessels of difierent kinds ; Fig. 11. — Spiial Vessels of Bhubarb. PLAINTS AND THEIR PBODUCTS. 25 and by means of these simple tissues all the wondrous pro- cesses of vegetable life are carried on. We may look upon the cells in their active state as nature's workshops — workshops invisible to the naked eye, silent, and mysterious ; but yielding results, in variety and effect, such as the highest ingenuity of man could never have con- ceived. The staple produce of the cells in one plant may be starch, of those in another plant sugar; some plants yield medicines, others gums and resins ; others again are perfume-factories, others colour-makers ; but all the various products are made from the sap elaborated first by the leaves from the elements of water, and air, and a little earthy matter taken up from the soil. CHAPTER V. ROOTS AND THEIR FUNCTIONS. EooTS serve the double purpose of fixing the plant to the soil, and of absorbing the food and moisture necessary to its growth. It is the nature of the root to divide itself into branches and fibres, which spread beneath the ground. If we examine the sides and extremities of these under- ground branches, we shall find a number of delicate rootlets. The free ends of these rootlets are soft and spongy, and these are the parts by which the plants mainly absorb moisture. That roots absorb fluid very Ks. 12.— Tip of rapidly may readily be shown by taking a ^fied^^"^^'""^^" small growing plant, and, after cleansing of earth, immersing the roots in water. Of the water ab- sorbed, however, but a small portion is retained by the plant, 26 NATURAL HISTORY OBJECT LESSONS. the greater part is sent out again by the leaves. This is probably owing to the fact that the solid mineral matters, which constitute an important part of the food of the plant, are dissolved in the water in very minute quantities, and to get a sufficient supply of these matters more water has to be absorbed than is necessary for the wants of the plant. Roots sometimes serve as winter storehouses for nourishing matter on which the plants feed in the ensuing year. Such are the fleshy roots of the turnip, carrot, parsnip, and raddish ; and the tuberous root of the dahlia. Other roots supply only the present wants of the plant, that is, they absorb only. Such are the Hbrous roots of trees, and bushes, and grasses. There is a close connection between the kind of root, and the duration of life in a plant. Trees and shrubs all have branching roots, which finally end in tender fibres, or rootlets. These roots are needed mainly for absorbing nourishment from the soil. Herbs, viz., plants of soft texture, having little wood in their stems, and in our climate either dying down to the ground, or else perishing altogether in winter, have roots which vary in kind as the plant is an annual, biennial, or perennial. Annuals grow from the seed, blossom, ripen their seed, and die in the same season. Such plants have fibrous roots in clusters, or a maia root branching into slender fibres. Bien- Fig. 11.— Dainia Koot nials do not blossom the first season; they live over the winter, flower in the second year, and then die when they have ripened their seeds. In the Fig 13.— Tap Root of Turnip and Carrot. PLANTS AND THBIE PEODUCTS. 27 first season these plants prepare a store of food, wMch is to be expended the next season in producing flowers and seeds. The plant-food is usually stored up in the root, as we have shown ; but it is also sometimes found in the short stalk and leaves, as in the cabbage. Perennial herbs usually Fig. 15. — Branching Root. Fig. 16.— Fibrous Root. Buttercup. die down to the ground as winter sets in ; but some portion of the stem with buds, as, for instance, in the dahlia (Fig. 14), is kept alive underground till the following spring. In these cases a stock of nourishment is laid up in the roots, or elsewhere. CHAPTER VI. STEMS AND THEIR USES. We may classify Stems according to either their various Forms, or their Internal Structure. The vast majority of plants have their stem erect. They elevate the leaves and flowers into the most favourable posi- sion for receiving the influence of the light and air, on which their due actions depend. Other stems are prostrate or trailing, as that of the garden nasturtium ; creeping, as in the strawberry-runners, or the offsets of the houss-leek ; 23 NATURAL HISTORY OBJECT LESSONS. as in the scarlet-runner, hop, honey-suckle, and convolvulus ; or climbing, as that of the ivy, the pea, and grape-vine. Twining plants- rise by coiling themselves round any Fig. 17. — Strawberry. Fig. 18.— House-leek. object for support, and it is a curious fact that plants of the same kind always coil in one direction, while plants of -The Convolvulus. Pig. 20.— The Hop. another kind may coil in the opposite direction. Thus, the convolvulus stem coils from left to right,* and the stem of the hop from right to left. * Namely, to a person supposed to be in the centre of the coil. PLANTS AND THKIR PEODUCIS. 29 Climbing plants lift themselves up by means of tendrils, as in the pea and grape, or by tiny rootlets as in the ivy. Fig. 21. —Sweet-pea, showing tendrils. Fig. 22. — Ivy, showing rootlets. In the Virginia creeper the end of each tendril spreads out into a little disc, which acts like a boy's sucker, and fixes Fig. 23. — Virginia Creeper, suckers magnified. the plant firmly to the wall. Some plants have their stems underground. Such stems send branches upwards at short 30 NATURAL HISTORY OBJECT LESSONS. distances into tlie air. Mint, couch-grass, and Solomon's seal are good examples of underground stems.* Fig. 25. — Root stock. Solomon's seal. iJ'ig. M. — L'oui;li-graSii. One of the most remarkable forms of the stem is that which presents itself in the potato. The potato plant has a portion of its stem underground, and this part sends out both roots and real branches (see Fig. 26). It is at the ends of these branches that potatoes are formed. If, when the stem of the potato plant is about a foot above ground, a portion of the stem is covered with earth, the covered portion will send out branches on which potatoes will be formed as well as roots. Every part of the potato- plant except the tuber dies off on the approach of winter ; and the tuber is the special provision made by the plant for the reproduction of its kind next year. The eyes of the potato are real buds, and the solid flesh of the tuber * For further information on kinds of stems see Murohe's " Botany," page 18. PLANTS AND THEIE PRODUCTS. 31 consists mainly of starch, the destined food of the young plant. There are some other forms of stems commonly looked upon as roots, such as bulhs and corms. Bulbs are really buds* covered with scales They grow underground, or partially so, as in the lily and onion. A conn is in form much like a bulb, only it is solid. It is a flattened under- ground stem. The crocus and snowdrop are fami- liar instances of the corm. We have seen that plants are composed for the most part of cellular tissue, woody tissue, and vascular tissue. Pig. 26.— Potato. Fig. 27.— Bulb. Lily. Fig. 28 —Corm. Crocus. The cellular tissue makes up the soft parts of plants, the woody and vascular tissues form the harder fibrous parts. "We have noted also (page 20) that the arrangement of these tissues in the stem is one of the distinguishing marks in the general classification of all plants into sub- * For the nature of buds see p. 38. 32 NATURAL HISTORY OBJECT LESSONS. kingdoms. In Exogenous plants, whether herbs or shrubs or trees, the icoody bundles are arranged round a central pith of cellular tissue, and the whole is enclosed by a layer of bark. In the first year there is no difference in. the growth of the stem of the herb and the tree ; but in the case of the latter a new layer of wood is formed in the second year out- side the layer of the first year between it and the bark, and so on : year after year a new layer is formed. Hence it is that the number of layers in an exogenous stem tells the Fig. 30.— Section of Flax. Fig. 29.— Section of Oak. Fig. 31.- Section of one-)'ear-old Oak. age of the tree. It must not be supposed that the woody layers consist entirely of woody tissue ; on the contrary, thin walls of cellular tissue extend irregularly from the pith to the bark. In a section of a stem these walls look like rays, radiating from the centre, and hence are called medullary rays. Cabinet-makers speak of these rays as the silver grain of the wood. Much of the beauty of polished oak depends on these medullary rays. The Bark of Exogenous stems consists of two layers. The outer is formed of cellular tissue. In some plants, as in the PLANTS AND THEIR PRODUCTS. 33 cork oak, this layer is very thick. The inner layer consists of woody tissue intermingled with loose cellular tissue. This layer forms a tough material, which, as we shall see later on, is much used in the manufacture of textile fabrics. Flax and hemp are the inner layers of the bark of the flax and hemp plants. But how and from what material are the layers of wood formed ? If we strip ofE the bark from a branch, say of willow, in the spring of the year, we find between the bark and the wood a sticky semi-fluid. From this the cells are formed, soft and thin-walled at first, but gradually Fig. 32 —Section of Cane. Fig. 33.— Section of Palm. becoming hard and tough by the deposit of woody matter on their interior walls. The new wood thus formed is at first softer, and lighter in colour, than the older layers, It is known as sap-wood, while the first-formed layers form the heart-wood. Endogenous stems consist of cellular tissue with the woody fibre arranged in bundles running lengthwise, and scattered throughout the whole thickness of the stems. A longitudinal section shows these fibres of wood to be long bundles ; on the cross sections these ends appear like so many dots. The wood increases in amount as the stems grow older by the formation of new woody fibres among the old. Endogenous stems rarely branch ; the asparagus stem is the C 6i NATURAL HISTORY OBJECT LESSONS. only common example in this country which branches freely. Most of the Endogenous stems are peculiar to hot countries, the palms being the most conspicuous examples. The commonest Endogenous plants of this country are the Fig. 34.— Stem of Tree-fern. - Section of Stem of Tree-fern. grasses (including the various kinds of grain), the asparagus, and the lilies. The best example of the Acrogenotjs stems, or summit yroivers, are the tree-ferns. The tree-fern produces a crown of leaves at the summit, and it is the bases of these leaves, or fronds as they are called, which increase the length of the stem. The woody tissue is curiously arranged in a broken irregular circle near the outside of the stem. CHAPTER VII. LEAVES AND BUDS. A complete Leaf consists of a hlade, or expanded portion, a petiole or foot-stalk, and a puir of small leaf-like expansions — the stipules — at the base of the foot-stalk. Many leaves have no stipules, some have no foot-stalk; and in a few the petiole and blade are undistinguishable. PLANTS AND THEIR PRODUCTS. 35 Leaves are either simple or compound. In a simple leaf Fig. 36.— Simple Leaf, with Stipules. Fig. 37. — Compound Leaf of Rose. the blade consists of one piece ; in a compound leaf the blade consists of more than one piece. Like stems, leaves are made up of fibrous and vascular sgnar psgngonr. Fig. 38. — Compound Leaf, Horse-cliestnut. Fig. 39. — Transverse Section of Leaf. (vessel) tissue, and cellular tissue. The ribs or veins which constitute the framework of the leaf consist of fibro- vascular 36 NATURAL HISTORY OBJECT LESSONS. tissue, and the green pulpy portion which fills up the inter- stices, and is spread over the framework, consists of cellular tissue. The whole is protected by a thin, transparent skin called the epidermis. The framework of the leaf is double. This may often be demonstrated in leaves which have lain in a damp ditch during the winter ; the cellular substance has decayed, and so the cohesion between the upper and lower layers is de- stroyed, and the finger may be pushed between them. The stouter pieces of this double framework are called rihs, the thinner pieces are called veins. Some leaves have one stout mid-rib run- ning through the middle of the blade, from the pe- tiole to the point, and from which veins branch ofi"; other leaves have several ribs of nearly the same size spreading out from the petiole. Leaves of both these kinds are net- veined, Fig. 40.-Reticulate Leaf7 The Mallow. "^ . reticulated, because the veins branch off from the rib or ribs, and divide again and again, forming meshes of network throughout the leaf. Such leaves charac- terize Dicotyledonous plants, viz., those the seeds of which have a pair of seed-leaves, and the stems of which are exogenous. Some leaves, again, have ribs which run side by side with- out branching, or with very minute veinlets, from the foot- stalk to the point of the blade ; such are parallel-veined leaves. These are characteristic of monocotyledonous plants, viz., those with one cotyledon attached to the embryo, and with endogenous stems. In some of the monocotyledonous PLANTS AND THEIR PEODUCTS, 37 plants the veins run parallel from a mid-rib to the margin of the blade. The surfaces of leaves are studded with openings communi- cating with air cavities within the substance of the leaves. Fig. 42— Stomata. Fig. 41. — Parallel-veined Leaves. Fig. 43. — Vertical Section through a Stomate. These are called stomata, or stomates, or breathing pores. They are surrounded by very delicate cells — usually kidney-shaped — which have the power of opening and closing the orifice. In dry weather the special cells collapse, and their sides touch each other ; in moist weather they swell and lengthen and curve outwards in the middle, so as to leave an oval opening. 38 NATURAL HISTORY OBJECT LESSONS. The storaata are most abundant on the under surface of leaves. Occasionally they are entirely absent from the upper side. They vary in number in different plants, from a few to many thousands to every square inch. Their office is evidently to regulate the passage of air and water to and from the leaf, hence they are seldom found in plants which grow under water. Leaves exhibit an almost endless variety of forms in different plants. Botanists name them, for the purpose of Fig. 44. — Bud of Horse-chestnut. Kg. 45. -Section of Bud of Iris. Fig. 46.— Section of Lilac Bud. cgtre^^ Fig. 47.— Section of Sage Bud. correct description, according to (1) the general outline of the blade, (2) the point of the blade, (3) the margin, and (4) the lobing or division. The Bud is the cradle of the young plant ; it is, in fact, a rudimentary branch. In biennial and perennial plants buds are formed towards the close of the growing season (viz. in autumn) in the axils of the leaves. They are protected from the frost during winter, usually by a covering of scales. PLANTS AND THEIR PRODUCTS. 39 In plants which grow in hot countries, and enjoy, so to speak, no annual repose, the buds have no specinl covering. The tiny leaves are wrapped up in the bud in various ways, but always in the same way in the same plant. [See Figs. 45—47.] CHAPTER VIII. FLOWERS— THEIR PARTS AND USES. The roots, stem, and leaves are more especially organs for the growth and nourishment of the plant ; the Flovi^ers have for their special office the production of new plants ; they are the organs of reproduction. As already pointed out in Chapter IT., these organs of re- production consist of four parts, calyx, corolla, stamens, and Fig. 48. — Section of Buttercup. Fig. 49.— Incomplete Flower. Anemone. pistil. The first two are non-essential : the stamens and pistil are essential organs. When all are present the flower is said to be a complete flower ; when one or more of the parts are wanting the flower is said to be incomplete. Some flowers ^ have a calyx, but no corolla ; while in some the ca^yx only is absent. Some have stamens without a pistil, and others a pistil without stamens : but as these organs are both essential to the production of seed, when one flower has stamens or pistils only, another plant of the same kind will bear flowers 40 NATTJEAL HISTORY OBJECT LESSONS. with pistils or stamens only. A few plants bear separate flowers of both kinds. Flowers exhibit great variety in form, in colour, in arrange- ment on their stalks, in the relative posi- tion and number of the various parts, &c. For all these the reader is referred to the simple text- book already re- ferred to. "We shall content ourselves here with looking at the general plan of flowers. The calyx or outer covering consists of a number of leaf- like bodies called sepals; thej' are usu- In some flowers the sepals are Fig. 50. — Incomplete Flowers in Catkins. ally of a green colour. of White Willow Fig. 51.— Mono- sepalous Calj'x. Fig. 52.— Polyse- palous Calyx. Fig. 53.— Polypetalous Corolla. combined, in others separate. The corolla or inner cover- ing consists of petah, a whorl of leaf-like bodies ; in some 1>LANTS AND THIEIR PRODUCTS. 41 flowers separate, in others more or less united, from the Fig. 54. — Monopetalous Fig. 55. — Stamens. Fig. 56. — Slamen. Corolla. Iris. Amaryllis. base upwards. The petals, which are generally coloured, stigma. Fig. 57.— Pollen Grain. Hollyhock. Fig. 58.— PoUen Grain. Phlox. Style. Ovary. • ■■« E.eceptaole. •■■'• Stalk. Fig. 59.— Stamens and Pistil. Fig. 60. — Pistil. are arranged alternately with the sepals. The stamens 42 NA-TURAL HISTORY OBJECT LESSONS. are arranged within the petals, and alternate with them. Each stamen has a sac, called the anther, which holds a powdery substance called pollen. The anther may be either sessile (without stalk), or supported on a stalk which is called the filament. The pistil is the central organ, Fig. 61.— Pistil of Five Carpels. Fig. 62. — Section of Ovary. Saxifrage. Pig. 63.— Adherent Ovary of Fuchi-ia. below and around which the stamens and floral envelopes are arranged ; it consists of one or more pai'ts, called carpels (fruits), either separate or combined. A simple pistil (one carpel) consists of a lower portion, the ovary, which includes the omiles destined to become seeds ; and an upper part, the stigma, a\ hich is a portion of loose cellular tissue without any skin covering. The stigma may be sessile on the ovary, or elevated on a stalk called the sti/le. In a compound pistil PLATSTS AND THEIR PEODUCTS. 43 tlie carpels may be either combined (grown together) or separate. All the organs of the flower are situated at the end of the flower-stalk, and this part is called the receptacle, or thalamus, or torus. In some flowers the receptacle is con- siderably expanded for the attachment of the floral organs. The calyx and corolla are designed simply to protect the essential organs of the flower from the efiects of rain, wind, or sun while they are young and tender. When the ovary has grown firm and strong, and moreover needs the warmth of the sun to ripen its seeds, the petals, and in most cases the sepals, die and fall ofE. But before this happens a change has been brought about in the ovules, whereby they have been changed from ovules to seeds. The processes involved in this change we know, but how they are eflfected is a mystery. The anther is essentially an oblong sac or box, divided longitudinally into two chambers — lohes as they are called. In these lobes the pollen grains are fully developed, and when ripened the anther itself bursts to let them out. But, while the pollen grains are maturing, the surface of the stigma has also undergone a change. It has become rough, and sometimes hairy, and is covered with a slightly sticky fluid. As the pollen grains fall from the bursting anther they are caught upon the stigma, the rough, moist surface of which prevents them falling off. Fig. 64.— 1 1, • • 1 i 1 Aiilher Very often the pollen grains are earned to the discharging stigma by bees and other insects, in their visits to Pollen. the flowers for honey, especially when the staminate and pistillate flowers are on difierent plants, or on difl'erent parts of the same plant. Under the microscope the pollen is seen to consist of minute simple cells. These cells vary very much in shape 44 NATURAL HISTORY OBJECT LESSONS. and colour in different plants, but are always alike in tte same plant. In every essential particular, however, they are the same. On the moist surface of the stigma they become Fig. 65. — Pollen Grains with. Tubes. Fig. 66.— Tubes of Pollen Grains penetrating the Tissue of the Stigma. active and grow. Each cell sends out a long slender tube, the pollen-tube, which slowly penetrates through the loose tissue of the stigma and through the style (when one is present) into the ovary. Into this pollen-tube the active vital fluid of the pollen-cell passes to the ovule, which thus becomes fertilised. CHAPTER IX. FRUITS AND SEEDS. In the flower, as we have seen, the ovary, consisting of one or more carpels, contains the oviiies. After fertilisation the PLANTS AND THEIR PK0DUCT8. 45 ovary is called the seed-vessel, and the ovules become seeds in name. But before the young seeds arrive at maturity many and important changes take place, especially in the parts which enclose and protect the seed. The receptacle, the calyx, as well as the carpels, play an important part in the production of " fruits " of various kinds. It should be noted that the walls of the carpels consist of three layers, the endo- carp, the mesocarp, and the epicarp, that is, the inner, middle, and outside layers. These are not easily distin- guished in the early stage, but are shown very distinctly in the ripe fruit. Thus in the plum or cherry the hard shell which immediately encloses the seed is the endocarp, the luscious pulp is the mesocarp, and the thin outer skin is the epicarp. We may now examine more closely the formation of what are commonly called "fruits," "nuts," "berries," "pods," "seeds," &c. Such fruits as are produced from a simple pistil, in- cluding pistils formed of a single carpel or of several combined, may be termed simple fruits. And these are formed from (1) the ovary and calyx grown together, or (2) the simple ovary. To the former belong \^ie fleshy fruits, viz., the berries, the gourds, and the pomes ; to the latter belong [a) stone fruits, such as the cherry, and (S) dry fruits, such as grains and nuts. In berries, such as gooseberry, currant, cranberry, grape, &c., there is a soft, pulpy portion, which appears to be formed from the endocarp ; the epicarp and calyx grown together form the skin. The fruit of the qourd tribe of plants — the cucumber, melon. Fig. 67.— Section ■^ , , o • • 1 ii of Cucumter, vegetable marrow, &c. — is precisely the same showing the kind of fruit as the berry, except that the Seeds. rind is harder. The pome, including such fruits as the apple, pear, and hawthorn, is formed somewhat differently ; it 46 NATURAL HISTORY OBJECT LESSONS. comes from a compound pistil with a coherent calyx-tube. It is the calyx-tube which grows thick and fleshy, and makes the eatable part of the fruit. The real seed-vessels are five Fig. 68. — Horizontal Section of Apple. Fig. 69.— Vertical Section of Apple. in number, enclosed with parchment-like walls. Immediately surrounding the seed-vessels, and inside a circle of greenish lines, is the flesh of the core. This is formed from the enlarged receptacle of the flower. In the stone fruits or drupes, such as plums, cherries, peaches, apricots, and almonds, as has already been pointed out, the Fig. 70. — Section of Cherry. Fig. 71.— Section of Plum. " stone " is formed from the endocarp, the flesh from the mesocarp, and the skin from the epicarp. In the almond the middle covering becomes tough and leathery instead of juicy and pulpy. Dry fruits have no soft, fleshy layers ; they are either dehiscent or indehiscent, that is, they may split open in some PLANTS AND THEIR PRODUCTS. 47 regular way to discharge the seed, or they may remain closed till the seed begins to grow, or until the seed-vessel decays. (All fleshy and stone fruits are of course inde- hiscent.) Of the indehiscent dry fruits the achene, the grain, and the nut are the most familiar examples. The achene includes all ) F,ig. 72.— Achene of Buttercup. Fig. 73.— Key. Elm, Ash, Maple. dry, one-seeded, closed, small fruits, many of which are often mistaken for naked seeds, such as the little seed-like fruits of the buttercup. The grain is the same as an achene, except that the seed-vessel adheres firmly to the seed. Wheat, barley, maize, rice, and oats are examples. The nut is an achene on a larger scale, and the seed-vessel becomes a hard shell ; chestnuts, beechnuts, filberts, and acorns are examples. All these are enclosed, or partly enclosed, by an outer cover- ing, which forms no part of the real fruit. Some achenes, as the fruit of the ash, elm, and maple, have a kind of winged appendage ; these are called key fruits. Dehiscent fruits are known under the names of pods and capsules ; pods result from pistils formed of single carpels ; they usually split open lengthwise when ripe and dry. The pea family, the peony, and marsh-marigold are common examples. Capsules are formed from compound pistils ; 48 NATURAL HISTORY OBJECT LESSONS. they dehisce in various ways (see Figs. 74 to 79). One of the most interesting of the capsules is that of the poppy- Fig. 74. — Pea-pod. Fig. 75.— Fruit of Tulip. Fig. 76. — Capsule bursting. head (Fig. 79). On the summit we see the old stigma, which never falls off. When the fruit is ripe little cracks Fig. 77.— Capsules bursting. Fig. 78.— Capsule. Wall-flower. Fig. 79.— Capsule. Poppy. form all round the under part of the stigma, through which the seeds may be shaken out like pepper from a box. PLANTS AND THEIR PilODUCXS. 49 Other fruits less simple in their formation are called aggre- gated, accessory, and multiple fruits. To the first of these classes the blackberry and raspberry belong. Each single fruit is a collection of smaller fruits, each of which is a Fig. 80.— Blackberry. Fig. 81.— Section of Fruit- let of Blackberry. Pig. 82.— Straw- berry. drupe, like a cherry or plum. The strawberry is the best example of an accessory fruit • all the soft, fleshy part is *.*■..' Fig. 83. — Section of Strawberry. Showing Pistils and Stamen, Fig. 84.— Mulberry. simply the receptacle grown large and juicy, so that the fruit is not a berry at all. Scattered over the surface of the fleshy receptacle are the real fruits — small dry achenes like D 50 NATURAL HISTOET OBJECT LESSONS. those of the buttercup. The mulberry and pine-apple are familiar examples of multiple fruits. The mulberry is a cluster of small fruits just like the blackberry, only that the mulberry is formed from a cluster of flowers, and the black- berry from the numerous pistils of a single flower. In the mulberry the juicy pulp is produced from the calyx of each flower, and not from the pistil, as in the blackberry. The real fruit is an achene, like that of the strawberry ; it will be found embedded here and there in the pulpy flesh. SbKtion IE— lEtonomtc ^totiucts Qf plants. CHAPTER X. THE PALM-TREES. " From their noble aspect, and perhaps also from the sur- passing usefulness of several members of the group, the Palms have been looked upon as the princes of the vegetable world." It is impossible to over-estimate their utility to the inhabi- tants of the countries where they grow. Every part of the tree in its turn appears to be put to some profitabio use. They furnish food, clothing, shelter, timber, fuel, building materials, weapons, paper, starch, sugar, oil, wax, wine, tan- nin, dyeing materials, resin, medicines, and a host of minor products. The members of the tribe which furnish the most abundant economic products are the date palm, the cocoa-nut palm, the ojYpalm, and the sago palm. Besides these may be men- tioned the cabbage palm of the West Indies, the terminal bud of which furnishes a delicious vegetable ; the areca, or betel- nut palm of the East India Islands, the nuts of which are chewed as a narcotic ; and the gornuto palm of Southern Asia, the great source of palm wine. South America is pre- eminently the land of palms. Here, in the vast virgin forests of Brazil, flourish hundreds of diflferent species of palms yielding to the native Indians all they need in life for food, shelter, clothing, lights, and medicine. The Date-Palm. — The date-palm is one of the most noble and, at the same time, one of the most useful of this 52 NATURAL HISTORY OBJECT LESSONS. tribe of beautiful trees. Its praises bave been sung in every age and clime. It is the cbief source of the national wealth of the inhabitants of Arabia, and the borders of the great African deserf, the fruit being the staple article of food. The tree rears its column-like stem to a height of sixty feet or more ; and terminates in a crown of large, but graceful feathery leaves. Great flower stalks issue from horny sheaths, growing between the leaves and the stem, and bear small white flowers. The flowers are succeeded by the fruit, which hangs in great bunches several feet long. Dates vary in size, colour, and quality, as much as does the apple in our country ; while the recognised and named varieties of one fruit are as numerous as those of the other. The date harvest is looked forward to with as much anxiety as the vintage in France, or the corn harvest in England. Famine would follow a failure of the crop. The fresh fruit is eaten without any preparation. "Those who, like most Europeans at home," says a celebrated traveller in Arabia, " only know the date from the dried specimens of that fruit shown beneath a label in shop windows, can hardly imagine how delicious it is when eaten fresh, and in central Arabia. Nor is it, when gathered fresh, heating — a defect inherent to the preserved fruit everywhere — nor does its richness, however great, bring satiety ; in short, it is an article of food alike pleasant and healthful." In the oases of the Sahara, and in other parts of northern Africa, dates are pounded and pressed into cakes, which serve as a supply of food till the new harvest arrives again. The date-palm furnishes almost everything that the Arab requires in life. It gives a grateful shade in a land where the rays of the sun are almost insupportable. Camels, as well as men, feed on the fruit. An incision in the trunk yields a sweet liquor, which by fermentation becomes wine. The timber of the trunk is used for building purposes and in the manufacture of furniture. The leaves are used as thatch, and the foot- PLANTS AND THEIR PRODUCTS. 53 stalks as fuel ; while, in addition, ropes and mats and many other articles are made from fibres obtained from the leaves. Date-sugar, a valuable commercial product of the East Indies, is obtained from the juice of a species of palm closely allied to the date-palm. The CocoA-Ntrr Palm. — The cocoa-nut palm is a beauti- ful and lofty tree. Its column-like stem shoots up to a height of from sixty to a hundred feet, and terminates in a crown of graceful, waving, pinnate leaves. These leaves often attain a length of twelve or fifteen feet, and with their strong mid-ribs and numerous long, acute leaflets resemble gigantic feathers. The flowers are arranged in clusters five or six feet long, and they are enclosed in a tough spathe. The fruit is enclosed in a thick fibrous husk. Inside this is the hard shell, which protects the kernel, and the milk within. The cocoa-nut palm flourishes on the coasts of tropical countries : in the East and West Indies, on the shores of tropical America, on the shores of India and especially of Ceylon, and it finds a congenial home on all the warm islands in the broad Pacific. In Ceylon alone not less than twenty million trees are cultivated in plantations. " The first operation in cocoa-nut planting is the formation of a nursery, for which purpose ripe nuts are placed in squares containing about four hundred each. These are covered an inch deep with sand and sea-weed, or soft mud from the beach, and are watered daily until they germinate. Those put down in April are sufficiently grown to be planted out before the rains of September, and they are then set in holes three feet deep and thirty feet apart. They must be protected from the glare of the sun, and watered when necessary for the first two years. They begin to bear fruit in from five to seven years after planting, and the average produce of a fair- sized tree is sixty nuts yearly." * • Sir J. Emerson Tennant, on Ceylon. 54 NATURAL HISTORY OBJECT LESSONS. The uses to which, the various parts of this tree are put are almost endless. It has been not unaptly called the " tree of a hundred uses." The nuts are used for food, and the milky fluid serves for drink. The juice of the unexpanded flower-spathe forms an agreeable drink under the name of "toddy" or palm wine. From "toddy," sugar can be obtained ; and when fermented " arrack," a spirituous liquor, can be distilled over. The trunk yields the porcupine wood of commerce, and is made to serve every possible purpose from the manufacture of knife-handles to the construction of door-posts. The leaves are made into baskets, or used as thatch for the villagers' cottages ; and the leaf-stalks serve for garden fences. The kernel yields the valuable cocoa-nut oil used in the manufacture of candles, and the fibrous husk is made into ropes, brushes, matting, &c. For the preparation of the oil the kernels are first broken into small pieces and dried in the sun ; one thousand full- sized nuts yield about five hundred pounds of these dried pieces, named copice, and these yield by pressure, or boiling, about twenty-five gallons of oil. At ordinary temperatures this oil is a white solid ; under great pressure the more liquid oil is squeezed out, and hard cocoa-stearin for candle- making is left behind. Marine soap, which will form a lather with sea- water, is made from cocoa-nut oil. The value of the cocoa-nut oil imported every year from Ce3'lon and India alone amounts to upwards of £300,000. The Oil-Palm.- — The oil-palm tree grows principally in the countries bordering the West coast of Africa, and palm- oil is the chief article of commerce of the West African ports. The fruit is borne on dense heads, sometimes two feet or more in length and two feet in circumference. The fruit itself is similar in size and shape to the olive ; but is of a beautiful golden-yellow colour. The seeds are enclosed in a hard shell, and the shell is covered with a fleshy fibrous rind. It is from this rind that the best oil is obtained. The PLANTS AND THEIR PRODUCTS. 55 fruit, when ripe, is boiled in earthenware pans and then crushed. The crushed mass is then placed in large shallow clay vats nearly filled with water, and women tread out the oil, which comes to the surface. , The oil is collected, boiled to get rid of the water, and then packed in barrels for export. Good palm-oil possesses a bright orange colour ; and, when it arrives in this country, has the consistency of butter. In Africa it is used for food; in England it is bleached and manufactured into candles and soap. It is also used for greasing the axles of railway carriages. The annual iraporr of palm-oil from the west coast of Africa exceeds £1,000,000 in value. CHAPTER XI. GRASSES— THE CEREALS, THE SUGAR-CANE, THE BAMBOO, The general appearance of the ordinary grasses is familiar to us all. The long narrow leaves, and the hollow-jointed and cylindrical stalks, serve to distinguish them from all other plants. To the grass tribe belong not only the numerous and varied grasses of our meadows and hillsides, but also all those grains, such as Wheat, Rice, Maize, Barley, Oats, Rye, and Millet, which are used as food for man and beast, together with the juicy Sugar-cane and the tall Bamboo. The grasses are very widely distributed, being found in every quarter of the globe ; and they constitute by far the most important group of plants in the vegetable kingdom. Wheat is the most extensively grown, and thS most important of all the cereals. It is largely cultivated in the United States, in Canada, in most European countries, 56 NATURAL HISTORY OBJECT LESSONS. especiallj' in France and Russia ; in India, in Australia, and in many other countries. There are many varieties of wheat, following chiefly from the differences in the conditions of soil and climate under which the plant is cultivated. The chief are hard wheats and soft wheats, which are sown in the autumn ; and the spring wheat sown in the early months of the year. Spring wheat, like barley, is bearded. The grain of hard wheat is harder and drier, and keeps better than that of the other kinds ; but soft wheat yields the whitest flour, and sells at a higher rate. Hungarian flour is generally considered the best in this country. As an article of food wheat is more largely consumed than either maize, rice, oats, barley, or millet, — although some of the latter contain a larger percentage of nutriment, and are far cheaper, — and probably for this reason, wheaten flour alone is well adapted to make fermented bread. The chief sources of supply of wheat and wheaten flour for Great Britain, taken in order, are the United States, Russia, Germany, and Australia. Rice is believed to be a plant native to India : certainly it has been cultivated there from the very earliest times. Naturally a marsh plant, rice requires a damp soil, and moist, hot atmosphere to bring it to perfection. Hence it is culti- vated in the low plains and great river valleys of tropical and sub-tropical countries, which are either periodically flooded, or which admit of easj- and copious irrigation. The method of cultivation varies in different countries. In the States it is sown in trenches in sirring, and the ground is then flooded for several days. When the young plants are a few inches high a second flooding is given, and again when the harvest time is approaching the flooding is repeated. In some countries the seeds are scattered as the floods are subsiding, and tlio grains sink into the mud and speedily germinate. In Lower Bengal, in July of each year, hundreds PLANTS AND THEIR PEODUCTS. 57 of square miles of rice-fields maj' be seen covered with water from the overflow of the Ganges, the ears of grain floating on the surfdce of the water. The finest rice is grown in the rich swampy lands of North and South Carolina. The Patna rice of Bengal ranks next in quality. The chief rice-growing districts in the world are China, India — especially in the valleys of the Ganges, Irawadi, and Brahmaputra — and the United States of America. Much of the rice is imported in the husk as a protection against injury in transit. In this state it is called paddy. " Rice is second only to wheat as an article of human diet, and forms the chief nutriment of at least one-third of the inhabitants of the globe. It is admirably adapted to the wants of the inhabitants of the tropics as it is not so heating to the human system as any other cereal, and it is a specific for diarrhoea and dysentery, which are so prevalent in those climates," India and Burmah are the chief sources whence we draw our supplies of rice. Maize, or Indian-corn, is a plant of the new world.* It is most extensively cultivated in the United States and Mexico. There are many varieties of maize which difier among themselves as much as they differ from the other cereals. They vary in height, — from ten inches to ten feet ; in time of coming to maturity — from two to seven months ; in shape and size of ears, and in the colour of the grain — which may be white, yellow, purple or even striped. It requires a warm climate and a rich soil to bring it to perfection. Its cultivation is simple, and the returns very large, its produce being greater than that of any other grain. As an article of food Indian-corn flour is very extensively used. It is not well adapted for making bread ; but is * It is probably a native of Mexico. 58 NATURAL HISTORY OBJECT LESSONS. sometimes mixed with wheaten-flour for that purpose. The grain contains a larger proportion of oil than any other corn, and is therefore possessed of remarkable fattening properties. Deprived of its gluten it becomes corn-flour* One kind of "sweet" maize is grown in the States for boiling in its green state as a culinary vegetable like green -peas. Not less than 18,000,000 bushels of maize are grown in the States annually, of which about 200,000 are used in the manufacture of starch. Barley, Oats, Eye. — These cereals are much hardier than wheat or maize, and hence they flourish in colder climates. Barley is cultivated extensively in Russia, Roumania, Germany and Denmark, and in our own country ; oats in Russia, Sweden and Scotland ; and rye in Russia, Germany and Holland. Barley is used mainly for making malt for brewing beer, and distilling spirits. Barley-meal, or barley-flour, is used as a fattening food for pigs and other animals. Pearl-barley is made by grinding ofl" the husks in mills adapted for that purpose. Oats form an exceedingly wholesome and nutritious article of food. The kiln-dried grain, from which the husks have been removed, ground into coarse meal, is known as oat-meal. The people of Scotland eat oat-meal extensively in the form of porridge. The greatest consumption of oats, however, is as food for horses. Rye- meal is largely used among the poorer classes in Russia for making rye-hread — a bread which is dark in colour, coarse, heavy and unpalatable. Millet is grown in India, Egypt, Italy, Spain, and in Asia Minor, and Arabia. One species is known under the name of Dhurra. In many Eastern countries millet is used for food ; in this country it is used for feeding poultry. The Bamboo is the giant of the grass tribe ; but in every respect it is a grass. The stem is hollow like that of most * See chapter on Starch, page 62. PLANTS AND THEIR PEODTJCTS. 59 other grasses, and it forms at intervals the same joint or knot. The flower also is enclosed in a couple of bracts or scales, which serve the place of petals just as in common grass. It grows almost everywhere in the tropics. China seems to be its natural home ; but it is abundant in India and the East India Islands, and it forms dense jungles in the valleys of the Andes. There are many species of bamboo ; the most common has a slender hollow knotted stem 40, 60, or even 80 feet long, having any thickness up to 18 or 20 inches. The stems grow very fast, extending to its entire length in a few months. Many columns rise from the same root, and from the higher joints ; and when the stem has reached its full length there springs a set of smaller branches or shoots. These shoots are also jointed and another series of smaller shoots spring from these again, and so on, until the last shoot is nothing more than a narrow pointed leaf. As each bamboo in the thicket sends out shoots in like manner, a thick almost impenetrable mass of feathery-looking foliage is forme.d- The bamboo is one of the most useful plants that nature has given for the use of man. The soft vigorous shoots are eaten like asparagus, or they are salted and eaten with rice, or candied and eaten as a preserve. The seeds are some- times eaten, especially when rice is scarce. It is the stem, however, which is the more abundantly useful part of the bamboo. In China, India, and Japan it is made to serve purposes almost innumerable. The Chinaman builds his house of bamboo, and furnishes it, even to bedsteads and bedding, with the same material. With the outer part of the stem the Chinese and Japanese manufacture wicker work unequalled for beauty and neatness of workmanship, and the inner parts are beaten into pulp for making the finest paper. The bamboo is also used for making the sails, cables, and rigging of the junks that stud the rivers and canals, for the manufacture of implements of husbandry, for 60 NATURAL HISTORY OBJECT LESSONS. building bridges, for constructing water-pipes, and even for making buckets and bottles. The Sugar-Oane is another of the very valuable members of the grass tribe. The cane is a stem of grass jointed as in all other grasses ; but it grows to a height of 12 feet or more, and measures 4 or 5 inches round. It is propagated mainly by cuttings, and the canes attain their full growth in from twelve to fifteen months. The stalks are surmounted by pale lilac flower-heads from 1 to 2 feet in length, so that a field of canes in full bloom is a pretty sight. Unlike our meadow grasses and the various cereals, the stalks are solid, being filled with pith. This pith, when the plant is in a mature condition, contains about 90 per cent, of juice. It is from this juice that sugar is obtained. When ripe the canes are cut down, and at once carted to the crushing mill, where they are crushed and squeezed between large iron rollers. The expressed juice is a solution in water of from 12 to 20 per cent, of sugar, with traces of other substances, albumen, gum, a peculiar substance re- sembling gluten, and the usual mineral ingredients. The process of separating the sugar from the juice is somewhat complicated, but the principle is very simple ; a little quicklime is added, and the juice is passed at once from the vessels in which collected to evaporating-pans or large copper boilers where it is boiled. The boiling causes the albumen and gluten to coagulate, just as the white of eggs coagulate on boiling ; and this rises to the top as a thick scum and carries most of the impurities with it. The scum is removed, and the juice is now passed on to other vessels, where it undergoes similar processes of boiling and skimming. As the water is gradually driven off as steam the juice thickens, and when it becomes about as thick as oil, the syrup is poured into shallow pans and allowed to cool. As it cools the sugar separates from the liquid in small crystals, and the former is drained off. The crystals PLANTS AND THEIR PRODUCTS. 61 we call raw sugar, and the liquid drained off molasses, or treacle. It takes from 12 to 14 tons of good ripe canes to yield 1,500 gallons of juice, from which about a hogshead of sugar is obtained. Much of the sugar is left in the canes, and some is lost during the boiling, so that in practice less than one-half of the sugar contained in the canes is secured. When the canes have been cut, others spring up in their places ; but the plants require to be renewed every six or seven ye^xs. The canes diminish in size and length every year ; but yield a richer juice. The sugar-cane is cultivated in most tropical countries where there is sufficient moisture. It is grown most exten- sively in the West and East India Islands, in the United States, in the Mauritius and in Brazil, and from these coun- tries we draw our chief supplies of sugar. The total yearly import of sugar into Great Britain is about twenty million cvrt., valued at about twenty million pounds. Sugar is also manufactured from the juice of several other plants, the chief of which are the beet-root, sugar-maple, palm-trees, and sugar-millet. The sugar obtained from all these plants are called " cane-sugars." * Beet-root sugar is manufactured in Germany, France, Austria, and Russia, to the extent of li million tons yearly. Sugar is extracted from the sap of the sugar-maple, but mainly for home consumption in the United States [Northern]. In the West Indies, India, and Ceylon, sugar is made from the juice of the flower-buds of palm-trees, and in China from the sugar-millet. * To distinguish them from the grape-sugar— a sugar obtained from grapes and other fruit, much less soluble in water than cane sugars. 62 NATUEAL HISTORY OBJECT LESSONS. CHAPTER XII. STARCHES. Staech exists in all plants. It is stored up in tte cells for the purpose of nutrition, and is met with in great abundance in the seeds of the corn-tribe, in peas and beans, in the tubers of potatoes, in the tuberous rhizome of the arrow -root plants, in the pith of the sago-palm, and in the juice of the carrot, beet, &c. The starch generally assumes a granular form. The granules are transparent, and too small to be S3en by the naked eye. Under the microscope they present a variety of shapes and sizes according to the plants whence they are derived. Indeed it is quite possible to determine the source of the starch by the form and size of the starch granules. The starch grains are really little bags or sacs, which contain the true starchy matter. When put into hot water these sacs swell out and burst, and the contents are set free. This is why starch once dissolved can never be restored to its original form. Starch as sold in the shops for laundry purposes is either a white glistening powder, or it is in form of columnar masses easily reducible to powder. When pressed between the fingers starch gives a harsh feeling, and emits a peculiar crackling sound. It is heavier than water, and is insoluble in cold water, and in spirits of wine. Mixed with hot water it assumes the well-known viscous pasty condition, in which form it is used to stiffen Knen. Mixed with cold water, or f.old milk, and baked or boiled, it becomes converted into consistent piiddings. The principal kinds of starch used as food are arrow-root, tapioca, tous-Ies-mois, sago, and corn-flour. Arrow-root is the starch obtained from two or three species of arrow-root plants [Maranta]. These plants are PLANTS AND THEIR PRODUCTS. 63 Kg. 85.- Eice Starch. Fig. 86.— Wheat Starch. Fig. 87. — Maize Starch. Fig. 88.— Potato Starch. 64 NATURAL HISTORY OBJECT LESSONS. native to tlie American continent ; but are extensively culti- vated in most tropical countries. The best arrow-root is obtained from the West India Islands, St. Vincent being now the chief seat of the arrow- root culture. The arrow- root plant produces a scaly, white, tuberous rhizome ; and it is from this part of the plant that the starch is prepared. The rhizomes are gorged with starch grains, especially just before the period of rest ; and if collected at this time yield 25 per cent, of starch. They are carefully peeled before grating, because the skin of the rhizome contains a resin which would colour and give a disagreeable flavour to the arrow-root. Tous-LEs-MOTS, another kind of arrow-root, is obtained from the various species of Canna, a plant allied to the Maranta. Brazillian arrow-root is the starch obtained from the Cassava, or Manioc plant. When agglutinated into fine globules on hot plates, it forms the Tapioca of commerce. British arrow-root is prepared from potato starch. Sago is obtained from the soft cellular interior of the stem of the sago-palm. When the tree is full grown,* it is cut down, and the fat gummy-looking substance is extracted from the trunk. This is reduced to powder, mixed with pure water, and strained through fine cloth to separate the glu- tinous and woody matter. The starch, when separated from the water and partially dried, is passed through sieves to give it the well-known granular appearance of the sago of commerce. Almost all the sago imported into this country, about 300,000 lbs. a year, is brought from Singapore. Sago forms a wholesome and nutritious food ; but it is also used as a starch for textile fabrics. CoEN-FLouR is obtained from maize, or Indian corn. The grains are steeped in water ; and, when swollen, are crushed under water between cylinders. The mass is then passed * The tree is then about 30 feet high and 20 inchea in diameter. PLANTS AND THEIR PRODUCTS. 65 into sieves, when the milky-looking fluid holding the starch passes through, and the husky matter is retained. The former is conducted into settling tanks, where the starch gradually settles at the bottom. The liquid is next drawn o£F, and the deposit is purified by repeated washing and settling, and then separated from the water and dried at a gentle heat. The chief sources of starch for industrial purposes are potatoes, wheat, and rice. Potato Starch. — The manufacture of starch from pota- toes is an important industry in Germany, Holland, Russia, and America ; and, during the time when the potato disease was very prevalent, large quantities were made in this country. It is a curious fact that diseased potatoes yield as pure and useful a starch as the sound tubers. In order to extract the starch the potatoes are well cleansed, and then rasped by machinery. The pulp is received on a sieve, and is washed continuously by a gentle stream of water so long as the washings are milky-looking. The milkiness is caused by the granules of starch held in suspen- sion. The liquid is conducted into settling vats ; and, as in the case of corn-flour, the starch which settles is repeatedly washed, separated from the water, and dried at a gentle heat. Potatoes contain about 20 per cent, of starch and 76 per cent, of water. Wheat Stakch. — Rice Stakch. — In England starch is made chiefly from wheat and rice. The manufacture may be illustrated on a small scale by putting a small quantity of flour in a muslin bag, and working it with the fingers under water. The starch passes into the water and gradu- ally settles at the bottom of the vessel. Considerably more than the half of wheat and rice consists of starch ; but these cereals contain also another substance called gluten va. con- siderable quantities (12 to 20 per cent.). Formerly this gluten was wasted in the manufacture of E 66 NATURAL HISTORY OBJECT LESSONS. starch ; but of late years the practice has been to separate the gluten and starch by steeping first the grain and then the flour-paste in a very dilute solution of caustic soda. The fibrous matter of the grain is easily got rid of by stirring the mixture with water. The fibres quickly subside to the bottom, when the milky fluid containing the starch is run ofl^ into separate vessels, where the starch is deposited and the liquor drawn off. (The latter contains the gluten, which is separated by adding sufficient sulphuric acid to neutralize the soda. The gluten is used for feeding cattle.) After cleansing, a little blue colour is added to the starch, which on gently drying assumes the well-known columnar structure. Violet powder is scented starch. Starch baked at a moderate heat in an oven is soluble in water, and forms with it a kind of gum called Dextrin, or British Gum. Dextrin is used as a substitute for the more expensive Crura Arabic for a great variety of purposes. It is used for sizing paper, for stiffening cotton goods, for thickening colours used in calico printing, and also in the preparation of lozenges, labels, adhesive stamps, and surgical bandages. CHAPTER XIII. OILS AND FATS (VEGETABLE), Every species of plant produces an oil in more or less abundance possessing some characteristic property peculiar to itself. One property, however, distinguishes all oils. They are readily inflammable ; and, on burning, leave no solid residue.* Water boils at 212° Fahr. and becomes steam ; and the * Being composed almost entirely of hydrogen and carbon (occasionally oxygen is present), they produce by their full and free combustion in oxygen water und carbonic acid gas only. ' PLANTS AND THEIE PRODUCTS. 67 steam may be cooled into water again. Oils boil and be- come vapour at different temperatures, usually much higher than water. Thus oil obtained from orange peel boils at 345° Fahr., and oil of cloves boils at 480° Fahr. Now many of the oils cannot be heated to their boiling point under ordinary circumstances : they decompose into other sub- stances and give off offensive vapours. In other words, under ordinary conditions we cannot change them to vapour of oil, and hence cannot distil them. Such oils are called iixed oils. Those oils which can be vaporized without decomposition are called volatile oils. Olive-oil, palm-oil, linseed-oil, and cocoa-nut oil are examples of fixed oils. Oil of cloves, oil of mint, oil of turpentine, and oil of lemon are examples of volatile oils. To determine whether an oil is fixed or volatile, let a drop fall on a piece of clean blotting paper and heat the paper until it is slightly charred. If the oil disappears leaving no stain behind, it is all volatile : if a greasy spot remains, it is wholly or partially fixed. Fixed Oils. — Vegetable fixed oils are nearly all iluid at ordinary temperatures in this country ; but a few, which are liquid in the country of their production, are solid here : such are palm-oil, cocoa-nut oil, and Chinese tallow. Solid oils are sometimes termed fats. The fats and oils are all lighter than water, and all soluble in ether, oil of turpentine, and benzin. Hence these solvents are used to take grease spots out of cloth, &c. They render paper semi-transparent, producing what is well known as a greasy stain. The vegetable fats and oils occur in various parts of the plant ; but they are most abundant in the fruit and seed. Olive-oil and palm-oil are obtained from the fleshy fruit. The oils of linseed, hemp-seed, rape-seed, cotton-seed, are, as their names imply, all expressed from seeds ; and so like- wise are castor-oil, and poppy-oil. Oocoa-nut oil, and nut oils of various kinds, are obtained from kernels. 68 NATURAL HISTORY OBJECT LESSONS. Oils are extracted from nuts and seeds by simple pres- sure, by pressure after heating, and occasionally by the action of solvents. The oil obtained by pressure is called cold drawn, or virgin oil. Heating the crushed kernels or seeds renders the oil more fluid, and consequently it presses out more easily, but the oil is not so pure. The heat should never exceed 175° Fahr. When the oil is extracted by a solvent, a heavy colourless fluid called bisulphide of carbon is used. The bruised seeds are digested in the liquid, which dissolves the oil. The mixture is then distilled, when the bisulphide distils off in vapour at a temperature of 115° Fahr. Steam blown through the oil destroys all trace of the sulphur. The refining of oil is a separate industry. Several methods are employed. Perhaps the most simple is to add 2 or 3 per cent, of caustic soda to the heated oil. The soda forms soap with a small portion of the oil, which, rising to the top as scum, carries all impurities with it. Some fixed oils dry and become hard on exposure to the atmosphere, others do not dry. Hence we may divide the fixed oils into drying and non-drying. The various uses to which these oils are applied in the arts and industries depend on their drying or non-drying properties. Drying oils would be useless for lubricating machinery, and non- drying would be worthless for mixing paint and varnishes. The chief of the drying oils are linseed, poppy, hemp, and sunflower ; and the most important of the non-drying are palm-oil,* olive-oil, rape-oil, colza-oil, and castor-oil. Linseed-Oil. — Linseed-oil is obtained from the seeds of the flax plant, which yield about one-fifth of their weight of oil. This oil is of a light yellow colour, and possesses a slight peculiar odour. Owing to its powerful drying pro- perties, which are much increased after heating with a little red lead or black oxide of manganese, it is extensively used * For palm-oil see Oil-Palm Tree, page 54. PLANTS AND THEIR PRODUCTS. 69 in tlae preparation of paint. If heated for some time it is converted into a dark tenacious mass, which may be drawn out into threads. This, properly mixed with ground charcoal, constitutes printer's ink. Flax-seed, or linseed, is obtained principally from the East Indies and Russia, whence upwards oifour million pounds' worth are imported every year. The oils obtained from the Poppy, Hemp, Sunfi.owek, and Cotton are used for purposes similar to linseed-oil ; but cotton-seed oil and sunflower-oil are not good drying oils. Sunflower-oil, which is produced in vast quantities in Russia, India, and China, and more recently in Germany and Italy, is almost equal to olive-oil for table use. It makes soap of a superior quality, and the seeds are also used for fattening poultry. Rape and Colza oils are obtained from the seeds of plants of the cabbage family. They are used chiefly for lighting purposes. Olive-Oil. — The olive-tree grows wild in the countries bordering the Mediterranean sea ; and the very name seems to suggest the idea of Palestine, and the sunny lands of the East. The fruit of the wild olive is not of much value. It is the fruit of the cultivated trees of Italy, Spain, and the South of France, which yields the valuable article of com- merce known as olive-oil. The common olive is an ever- green of from 20 to 30 feet in height ; but the cultivated trees are kept much lower by constant pruning. The fruit resembles damsons in size and shape, the fleshy part outside the stone being hard and thick. Un- ripe, the colour is yellowish blue or green, but changes to dark purple, or black, as the fruit ripens. The oil is obtained by pressure from the ripe fruit. That which is expressed from hand-picked fruit under light pressure is the most esteemed. It is called virgin oil. The common olive-oil is obtained by stronger pressure, or with the aid of heat, or after the olives, (having been collected into heaps) have remained till a kind 70 NATUEAL HISTORY OBJECT LESSONS. of fermentation has set in. A still inferior quality is obtained from the residue by boiling in water. This is used in the manufacture of soap. In many parts of Spain and Greece, and generally in Asia Minor, the ancient* custom of heating or shaking the tree to obtain the ripe fruit is still followed, with the result that the oil is of inferior quality. The olive-tree has in all ages been held in the highest estimation. It is frequently mentioned in the Bible, and the oil is associated with the corn and wine and milk and honey — the treasures of the Promised Land. Olive wreaths were used by the Greeks and Romans to crown the brows of victors ; and the tree is still universally regarded as the emblem of peace and harmony. Olive-oil is an insipid, inodorous, pale greenish-yellow coloured fluid, very inflammable, and not liable to turn rancid. It is the lightest of all fixed oils, and becomes solid at a temperature considerably above the freezing point of water. To a limited extent it is used in the preparation of food in this country ; but it may be regarded as the cream and butter of Italy and Spain. The unripe fruit of the olive-tree is pickled, and used as a dessert. Olive-oil is imported (almost exclusively from Italy, Spain, Turkey, and Greece) to the annual value of about one million pounds. Castok-Oil is a well-known viscous fluid. Where pure it has but a slight odour, and is almost colourless ; but it pos- sesses a very nauseous and disagreeable taste : it is obtained from the seeds of the castor-oil plant. This plant grows to a height of about five or six feet in England ; but in the West Indies it often reaches a height of twenty feet in one season. The seeds are about the size of horse-beans : when ripe they * " When thou beatest thine olive-tree, thou thalt not go over the boughs again ; it shall he for the stranger, for the fatherless, and the widow." PLANTS AND THEIR PRODUCTS. 71 are shelled and cruelied between rollers, and the crushed mass is put in hempen cloths, and pressed in a screw or hydraulic press. The oil which exudes is placed in water and heated to nearly boiling, when the gummy matter rises to the top as scum. The oil is then strained and bleached in sunlight, and is known as cold-drawn castor-oil. In India it is obtained in such abundance as to be used for illuminating, as well as for domestic and medicinal purposes ; and it is from India that we draw our main supply. YoLATii.E Oils are more or less aromatic, the scent being that of the plant from which the oil is derived. Formerly these oils were regarded as the subtle essence of the plant, and hence were called "essential oils." They are obtained chiefly from the leaves and flowers by distillation, and other methods ; but some are also extracted from the seed. The oils of orange and lemon are got by simple pressure from the rind. The volatile oils are mostly limpid liquids, lighter than water : they have an aromatic smell, and hot, burning taste : they dissolve freely in ether, alcohol, and mineral oils : they burn freely, with a smoky flame, are not greasy to the touch, and do not give a permanent grease-spot : they have high boiling points ; but in the presence of water or steam they readily distil over at a lower temperature. The volatile oils are used chiefly in medicine and per- fumery. Among the most common are oil of turpentine, the most valuable of all ; the oil of bergamot, obtained from the rind of the ripe fruit of the lime ; oil of carraicay, from carra- way-seed ; oil of cloves, from the unexpanded flower-buds of the clove-tree ; oil of lemon, oil of nutmeg, &c. Oil-Cake, viz., the refuse cake from which oil has been extracted,* contains a considerable portion of oil, the whole of the albuminous matter, sugar, gum, and starch of the seed. This forms in most cases a highly concentrated nutritious food for fattening cattle. The cakes from castor, mustard, 72 NATURAL HISTOEY OBJECT LESSONS. and croton seeds are unsuitable, because of tbe active principle contained in the oil. Linseed and rape-seed cake are the best. CHAPTER XIV. GUMS, RESINS, GUM-RESINS, GUTTA-PERCHA, INDIA-RUBBER. Gum exists in the juices of nearly all plants, and is present in such abundance in several as to flow in plenty from the barlf, when wounded, or when its surface cracks. The gummy exudations may occasionally be seen on the cherry and plum- trees of our own country. It is produced in its purest form by the various species of the acacia tribe. The name gum is applied only to those exudations which are entirely soluble in water, or which soften in water and form a thick glutinous liquid ; but which are not soluble in spirits of wine. Gum Aeabic when pure is transparent and colourless ; the commoner kinds have a yellow tinge. It has a glassy lustre and insipid taste, and is entirely soluble in water. It is imported into this country in large quantities on account of its extensive use in the textile manufacture, and in calico- printing. Gum arable is obtained chiefly from Egypt and Austria. Like gum arable, gum Senegal is obtained from a species of acacia, but is of inferior quality ; gum tragacanth, or gum dragon, is obtained from the stem of a prickly plant growing in Asia Minor, and is shipped from Smyrna. This gum is employed in some kinds of calico-printing. The common gum, used for labels, postage-stamps, en- velopes, &c., is made by baking starch at a moderate heat till it assumes a pale brown colour, and is soluble in water. A portion of sugar is added to enable the cement to be more readily softened on the application of moisture. PLANTS AND THEIR PEODUCTS. 73 Resins are solid inflammable substances which, like gums, are obtained from the stems and branches of trees ; but, un- like gums, are insoluble in water, and soluble in alcohol and the essential oils. They are more or less brittle, trans- parent, or translucent, and of a colour inclining to yellow. They are generally obtained by making incisions into the wood of trees which produce them, when they exude in the form of a thick liquid of about the consistency of honey. These liquids consist of resin dissolved in the essential oil of the plant, and to obtain the resin the essential oil is distilled off. Common turpentine consists of resin dissolved in oil of turpentine. When distilled with water the oil comes over with the steam ; and the residue, amounting to from 75 to 90 per cent, of the turpentine employed, is the common resin of commerce. The common turpentine is obtained from pine- trees ; and the pine-trees of the North American forests supply the world. Common resin is extensively used in the manufacture of soap ; and in the preparation of plasters and ointments. The oil of turpentine is used for diluting oil- colours, so that they will flow freely from the painter's brush. Yenice turpentine — a clear, transparent liquid — is ob- tained from the silver fir. Copal, lac, and mastic are resins obtained from tropical trees ; they are chiefly used in the preparation of fine varnishes for pictures and maps. Balsams are resins mixed with essential oil. Balsam of Canada is the nearly colourless liquid resin of a species of pine. Oum-resins are mixtures of resins, essential oils, and gums ; they are much used in medicines, and many of them are valued for their fragrance. Frankincense, myrrh, and gamboge are gum-resins. GuTfA-PERCHA * is the solidified juice of a tall tree which * From Malayan gutta = g(im, a.ni percha, tlie name of the tree; hencogum of the percha-tree. 74 NATURAL HISTORY OBJECT LESSONS. grows in the Malay peninsula and in the adjacent islands. The wood is soft, fibrous, and spongy, and useless as timber. Immediately after the rainy season the trees are cut down ten or twelve feet from the ground ; and the branches are lopped off to prevent the gutta from ascending to the leaves. Small pieces of the bark are now removed, and the milky juice or gutta runs out, and is collected. The juice rapidly hardens on exposure to the air. Usually it is boiled in iron pans, to get rid of water, before it is allowed to become solid. A large tree will sometimes yield from 30 to 60 lbs. of juice, but 30 per cent, of the weight is lost in drying. For manufacturing purposes the imported gutta-percha has to be purified. For this purpose it is heated by steam till quite soft, then torn to shreds and placed in water, when the impurities sink to the bottom. The gutta is now heated again, and kneaded and rolled, or pressed into blocks. During the last process certain substances, such as red-lead, 8ulphu>, and resin are added, either for colouring purposes or to increase the hardness. As prepared, gutta-percha is tough, strong, hard, and flexible. It is a trifle lighter than water, and possesses a peculiar odour. It softens on being heated, and becomes elastic. In this state it can be moulded to any form, becoming rigid again as it cools. It is highly inflammable, and burns with a bright white flame and much smoke, at the same time dropping a black residue which looks like sealing-wax. It is insoluble in water, spirits of wine, and dilute acids ; btit soluble in warm turpentine, and in cold naphtha. It is im- pervious to water, even in thin sheets, and a non-conductfor of electricity. Gutta-percha is used for a great variety of purposes — for soles of boots and shoes, for water-pipes, speaking-tubes, waterproof sheeting, picture-frames, cups, inkstands, &c., and for covering telegraph-wires. In the year 1883, 58,706 PLANTS AND THEIR PRODUCTS. 76 cwt., of the value ot £425,813, were imported from the Straits Settlements. Inuia-rubbek is the dried coagulated milky juice of various trees and shrubs. It exists in the sap of the net- work of lactiferous vessels of the middle layer of the bark. The best rubber is obtained by the careful evaporation of the recently strained juice at a moderate heat. The trees from which india-rubber is obtained grow freely in the tropics. The chief sources of supply are South America, Central America, the West Indies, Mozambique, West Africa, and the East Indies. The forests of the Amazon yield the best rubber, and immense cargoes are shipped every year from Pard, a town on the banks of this river. Various methods are adopted to coagulate the juice, de- pendent to a great extent on the species of plant from which the sap has been taken, such as the addition of alum, or hot water, or sea-water, or the juice of other plants ; but the juice of the siphonia, the Amazonian india-rubber tree, needs nothing but a gentle heat. The process of collecting and preparing in the Amazon forests is somewhat as follows : — The india-rubber maker, on finding sufiicient trees tolerably close together to be worth working, has first to make his "india-rubber path" through the trackless forest, that is, a path from tree to tree to the number he wants, generally about a hundred ; then he has to clear away the moss and creepers from the trunks so as to leave a clear space for " tapping." The trees are " lapped " with a small axe, slant cuts are made not quite through the bark, at about every eight inches of circumference, and under the incisions small tin, or other vessels, are fixed by means of clay. Tapping goes on with the week. On Monday the workman taps as higlvas he can reach, on Tuesday a foot or so lower, and on Saturday pretty nearly on the ground. The lower the 76 NATURAL HISTORY OBJECT LESSONS. tapping, the greater the yield ; that on Saturday is often nearly double that of Monday. The vessels having pre- viously been placed at the foot of each tree, the man goes out at daybreak, makes the incisions, and fixes his vessels. In the forenoon he collects his juices in a pail, and in the afternoon he " smokes," or makes his india-rubber. A small wood fire is made, and then fed with palm-nuts ; over this fire is inverted an earthenware pan of about the size and shape of a 12-inch flower-pot, except that the drainage-hole in the bottom is about 6 inches in diameter; the pan is tilted a little on one side to allow air to enter to the fire. Through the aperture a dense white smoke issues of a peculiar smell. The india-rubber maker now takes a mould or form, shaped according to taste ; this he dips into the milk ; or, if it be large, he may pour the milk over it. The mould, with some of the milk adhering, is now held and turned about in the smoke for about twenty seconds. By this process the milk is set into a fine thin layer of india- rubber. He continues dipping and smoking until his india- rubber is of the required thickness, or until all his milk is used up. It is then cut and taken oS the mould, and put in the sun and air to dry. At first it is of a dark cream colour, but gradually becomes darker. India-rubber loses about one- fourth of its weight in drying. Before being applied to its various uses in this country india-rubber has to be prepared. For this purpose it is softened by hot water and cut into pieces with sharp knives ; it is then passed between grooved rollers, over which either hot or cold water is made to flow. Solid impurities are thus crushed to powder and washed away. The rubber is now dried in a warm room and then kneaded or " masticated " by a machine. To convert the masticated rubber into rectangular blocks it is softened by heat, and then pressed into iron boxes or moulds. From these blocks sheets are cut by a machine. India-rubber in this form is elastic and waterproof, but it PLANTS AND THEIE PRODUCTS. 77 possesses the great disadvantage of becoming soft in hot, and hard in cold weather. It was soon found out, however, that the addition of a little sulphur prevented the material from being affected by changes of temperature. The process of adding sulphur is called vulcanisation, and the rubber is said to be vulcanised. The india-rubber is placed in melted sul- phur and subjected for about an hour to a temperature of 284° Fahr. At this temperature the rubber absorbs about one-tenth of its weight of sulphur, and becomes so changed in its properties that a temperature of 320° Fahr. scarcely affects it, and cold does not make it rigid. India-rubber may also be vulcanised by exposing the sheets to the action of chloride of sulphur. The sheets are either hung in a leaden cupboard to which the vapour of the chloride is introduced, or they may be dipped in a mixture consisting of one part of chloride of sulphur to forty parts of disulphide of carbon, without heat. India-rubber is soluble in benzol or wood naphtha, and ordinary mackintosh,* or waterproof cloth, is made by spread- ing on the textile fabrics layer after layer of the solution. If cotton or linen is used it is usual to incorporate sulphur with the solution, and then to vulcanise with steam heat. If silk or wool is used no sulphur is added ; but the dry coating of rubber is brought into momentary contact with the mixture of chloride of sulphur and disulphide of carbon. Double texture goods are made by uniting the rubber surfaces of two pieces by pressure between rollers. The fine vulcanised " spread sheets " are made by spread- ing layers of india-rubber solution, already charged with the requisite quantity of sulphur, on a textile base, previously prepared with a mixture of paste, glue, and treacle ; vulca- nisation is then effected by steam heat. By softening the preparation on the cloth by means of hot water the india- rubber sheet may be removed. * So called from Mackintosh, the inventor. 78 NATURAL HISTOEY OBJECT LESSONS. India-rubber is employed in an almost endless variety of ways— for articles of clothing, for tents and boats, for tubing and roofing, for the construction of bands and straps, for the manufacture of elastic web, &c. India-rubber is imported from many countries, but the chief supplies come from Brazil and the West Coast of Africa. The annual imports are valued at £3,500,000. CHAPTER XV. COTTON, HEMP, FLAX, JUTE. Cotton is the name given to the soft white down, or fine cellular hair, attached to the seeds of certain plants, which are indigenous to nearly all tropical countries. The cotton- plants belong to the same natural order as the common mallow, which grows abundantly in our own country. As supplying the raw material for our greatest industry, and for the clothing of all nations, these plants may well claim to be ranked among the most valuable of nature's produc- tions. The two chief kinds of cotton known in the commercial world are the Oriental, or Indian, and American. Most of the cotton plants are herbaceous, but a few are tree-like. One species grown in India and China attains a height of nearly 20 feet. The North American species are herbaceous : the seeds are sown in spring, and the cotton is collected from the seed pods as they burst in the autumn. The cotton most valued of all is " sea-island cotton," grown in the low-lying islands off the coast of Georgia. This surpasses all other cottons in length, strength, and beauty of staple. This cotton is now successfully grown in some of the Southern States, in Queensland, and in Egypt. PI/ANTS AND THEIR PEODUCTS. 79 Cotton Is picked by hand, and the down and seeds are removed together from the pods. The first process in the preparation of cotton for the market is to remove the seeds. This operation is called ginning. There are several kinds of coUon gins in use. The most simple is that which has long been in use in India. It consists of two wooden rollers placed close together between which the cotton is drawn and the seeds forced out. The saw gin consists of a grating of parallel bars on which the cotton is laid, and a series of circular saws which turn underneath the grating so that the teeth of the saws pass between the bars. The cotton is laid hold of by the teeth and drawn through, leaving the seeds behind. The cotton is swept off the saws by a series of stiff brushes turning beneath the saws. The ginning yields one-third of the bulk gathered from the pods as cotton fit for manufacturing purposes. This is pressed into bales for export. The seeds not required for sowing in the next spring are pressed for their oil, and the refuse cake is used for feeding cattle. The manufacture of cotton into cloth had its origin in the East. More than 2,400 years ago cotton was largely used in the manufacture of articles for clothing in India. The spinning, weaving, and dyeing was of the same primitive kind as that still practised ; yet the fabrics produced in the shape of gossamer-like muslins have never yet been equalled in this country. In Europe the cotton manufacture was first attempted in the commercial States of Italy, probably in the early part of the sixteenth century. From Italy it soon made its way to the Netherlands, and was thence carried to England by Protestant refugees about the beginning of the next century. It seems to have at once found a congenial home in South Lancashire, for we read in a book called " Treasures of Traffic," written in 1641, "The town of Manchester buys linen yarn from the Irish in great quantity, and weav- ing it, returns the same again as linen to Ireland. Nor does 80 NATURAL HISTORY OBJECT LESSONS. her industry rest here, for they buy cotton- wool in London that comes from Cyprus and Smyrna and work the same into fustians, dimities, &c., which they return to London, where they are sold ; and from thence not seldom are s»nt into such foreign parts where the first material may be more easily had for that manufacture." These goods were woven chiefly in Bolton, and sold in the weekly market to Manchester dealers, who finished the goods and sent them to London. The manufacture at this time was entirely by hand, and each weaver's cottage was a little factory. Linen yarn was used for the warp, and this was purchased already prepared. The female portion of the family carded and spun the cotton- wool for the weft, and the cloth was woven by the man and his sons. The examination of a piece of calico shows that the cMh is built up of threads interlaced at right angles (the long threads form the warp and the cross threads the woof). This points to the two great processes of the cotton -manu- facture, viz., spinning and weaving. Spinning is the making of the loose cotton fibre into thread or yarn, and weaving is the interlacing of the yarn to make cloth. The machines used in the manufacture of cotton goods are too intricate for any attempt at explanation to be made here, but the different processes may be briefiy explained. For making Tarn. 1. Mixing and scutching. — The cotton from several bales is thoroughly mixed. It is then torn and beaten in a machine to loosen the fibres, and to get rid of dust and dirt. 2. Carding, or combing. — By several combings and brushings the fibres are laid straight and parallel, and at the same time the short fibres are removed. The cotton leaves the carding machine in a thin ribbon-like film called a 3. Drawing. — Several slivers are placed toge^er and bv PLANTS AND THEIR PRODUCTS. 81 means of the drawing machine are stretched and drawn oui until they are no thicker than one was at first. 4. Spinning. — After one or two other processes by which the slivers are made longer, thinner, and stronger, and a little twisted, the material is spun into yarn. Spinning consists in still further drawing out, and twisting into threads. II. Weaving into Cloth. 1. Warping. — A number of reek, or bobbins, of yarn are wound by a machine in parallel order on a beam, to the length of from three to five hundred yards. This yarn will form the warp. 2. Sizing. — The thread is dipped in solution of starch in water to give further strength. 3. Reaming. — This consists in arranging and fastening the threads in the warp ready for the next process. 4. Weaving. — By this process the threads of the warp are interlaced by cross threads called the woof. The weft thread is carried backwards and forwards by a sort of reel pointed at each end, called a shuttle. Instead of passing the shuttle over and under each thread of the warp one at a time, every alternate thread is raised at the same time, and the shuttle passes under these and over the other half. Then the threads which were first raised are lowered, and the others are raised, and the shuttle is brought back passing under the threads it passed over before, and over the threads it passed under before.* Raw cotton to the enormous value of about £45,000,000 is imported into this country every year, the main sources of supply being the United States, Egypt, India, and Brazil ; and no less than four thousand five hundred million yards of cotton cloth, valued at upwards of £50,000,000, has been the average yearly export since 1880. Flax. — Linen is made from lint, or flax. Flax is the • For the further processes of bleaching and dyeing, see page 89. 82 NATURAL HISTORY OBJECT LESSONS. fibre of the inner bark of the Flax-plant — a pretty herbaceous annual growing about two feet high, and bearing bright blue flowers. The flowers are followed by rough seed capsules, each containing ten flat, oval, dark-brown seeds. The preparation of fl.ax from the flax-plant, and the manii- facture of linen is the most ancient of all the textile indus- tries. The " remains" of pre-historic times show that the fishing nets and lines were made of flax. Flax occupied a prominent place in ancient Egypt. We read that Pharaoh arrayed Joseph in vestures of fine linen, and the Egyptian mummy cloth was made entirely of flax. Pliny gives the following account of the preparation of the flax. "The stalks themselves are immersed in water, warmed by the heat of the sun, and are kept down by weights placed upon them, for nothing is lighter than flax. The membrane, or rind, becoming loose is a sign of their being sufiiciently macerated. They are then taken out and repeatedly turned over in the sun until perfectly dried, and afterwards beaten by mallets on stone slabs. That which is nearest the side, called sttijye (tow), is inferior to the inner fibres, and fit only for the wicks of lamps. It is combed out with iron hooks until all the rind is removed. The inner part is of a whiter and finer quality." The manufacture was introduced into England from Flanders in the thirteenth century, and thence into Ireland some four hundred years later ; and until the close of the eighteenth century, when cotton took its place, it was the most important of the textile industries. Gathering. — The plants are pulled up by the roots just before the seed pods are quite ripe, when they are just turning from green to pale brown, and when the stalks have become yellow through two -thirds of their length. The stalks are pulled hj the hand, and laid evenly in handfuls across each other. Rippling. — The first process is to remove the bolls, or capsules. This is done, usually on the field, by drawing the PLANTS AND THEIR PEODTJCTS. 83 stems ttrough a large iron comb fixed to a plank. The seed-vessels being too large to pass between the teeth are torn off, and fall into sheets placed beneath the rippling apparatus. Retting, or rotting. — The rippled stalks are now tied in small bundles and placed, roots downwards, in pure soft water, free from iron and lime, in dams or smalls ponds constructed for the purpose. The bundles are kept under water by a covering of rushes, or straw, or turf, on which stones are placed. In ten days, or a fortnight, the fibres become loosened and will separate from the woody core. The bundles are now taken from the water, and spread over grassy meadows for about a fortnight, during which time it is turned over. When dry the stalks are carefully taken up, and again tied in bundles, and stacked like corn. Scutching. — The next process is to separate the fibre from the woody core. This is done either by hand by thresh- ing with a wooden mallet, or in a machine by passing the stalks between grooved rollers. The woody portions are broken to pieces, and beaten and shaken out. Seckling. — By this process the flax is split up into the finest threads, cleansed, and arranged side by side ; while at the same time the short fibres are removed. The operation consists in drawing the fibres through a sort of brush made of fine steel needles instead of bristles. The long silky fibres which remain in the hand of the heckler are called line, and the short fibres collected by the brushes form tow. The flax is now ready for spinning. It was formerly the practice, especially in Scotland, for small farmers to grow flax in small patches, and to set, scutch, clean, spin, weave, bleach and finish the linen on the premises ; and the same practice still prevails in some countries. Large quantities of flax are grown in Ireland. The chief foreign sources of supply arc Russia, Belgium, Holland, and Grermany. The finest quality is obtained 84 NATURAL HISTORY OBJECT LESSONS. from Belgium ; but by far the largest supply is imported from Russia. Hemp. — Tbe hemp plant belongs to the same natural order as the common nettle and the hop. It is an annual herbaceous plant, the fibre of the bark of which constitutes the hemp of commerce. Much bast fibre of other plants is sold under the name of hemp, but the real hemp of commerce is obtained from Cannabis Sativa. It is supposed to be a native of India. It grows wild not only in India, but also in northern and western China, on the flanks of the central mountain chains of Asia, and in Russia near the Caspian Sea. It is now extensively cultivated in many European countries, especially in Russia, Italy, Holland, and Germany ; and in the United States. The plant yields three products : fibre, a resinous secretion, and seeds. The fibres are strong, tough, and flexible, and peculiarly adapted for weaving into coarse, strong fabrics, such as sail-cloth and canvas ; and for twisting into twine, ropes, and cables. It is prepared much in the same way as flax. The resinous secretion is developed on the leaves and flowers, but only in hot countries. It possesses medicinal and intoxicating properties, and has long been used in Oriental countries in various forms and preparations for chewing and smoking. From the seed about thirty-four per cent, of oil can be ex- pressed. This is much used in the preparation of varnishes and in the manufacture of soft soap. It is a drying oil, but much inferior to linseed oil. The cake is used for feeding cattle. The chief sources for the supply of hemp are the Philippine Islands, Russia, Italy, and Germany. Jute. — Jute hemp, or jute, is a textile material got from the inner bark of a plant belonging to the same natural order as the lime-tree.* It is extensively cultivated in * The inner bark of the lime yields bass or bast, from which Russian mats are manufactured. PLANTS AND THEIR PRODUCTS. 85 Bengal, the rich alluvial soil and hot moist climate of this province being very favourable to its growth. Unlike flax, the stalks are cut close to the root with a hook or sickle ; and the fibre is superior in quality when the crop is cut in flower. The fibre is prepared much in the same way as flax. The best jute is of a yellowish- white colour, silky in lustre, soft and smooth to the touch, and long and uniform in fibre. It is inferior to both flax and hemp in strength and tenacity, less even in fibre, and more woody, and not so easily bleached to a pure white. It is only recently that jute has come into extensive use in the manufacture of textile fabrics in this country. In India this manufacture has long been an important industry among the Hindoos. They make cordage, gunny-cloth, gunny-bags for packing, and even paper, from jute fibre. Dundee is the chief seat of the jute manufacture in Great Britain. Here the annual output of jute fabrics in the shape of sacking, hessians, tarpaulins, linings, backings for floor- cloth, rugs, carpets, &c., exceeds fifteen thousand miles. Almost all the jute, about three hundred thousand tons, is brought from India, Bengal alone supplying upwards of four million pounds worth. CHAPTER XVI. PAPER.* The origin and early history of Paper as a writing material is involved in obscurity. The art of making it from vege- * The word paper is derived from the papyrus, or paper reed, which formerly grew in the delta of the Nile. Prom this reed the Egyptians manufactured writing material. The stem was cut into slices, these were placed side by side, and then others across, the whole heing then steeped in water and pressed together, and polished by rubbing with smooth ivory or sheUs. 86 NATURAL HISTORY OBJECT LESSONS. table fibre reduced to a pulp appears to have been known to the Chinese as long as two thousand years ago. Paper was made from cotton by the Arabs in the eighth century. Its manufacture was introduced into Europe by the Moors in Spain, and the Arabs in Sicily. In Spanish writings it is called "cloth parchment," a term which well describes the thick material made from cotton fibre. As the manufacture extended northwards in Europe, away from the cotton-grow- ing countries, it became the practice to mix rags with the raw material. Linen also became a paper-making fabric. From the fourteenth century the manufacture of paper may be described as a European industry, and, from its extensive use, it may be inferred that it was made in England in the fifteenth century. The first paper-mills of which we have any record were set up at Hertford and Dartford in the sixteenth century. Paper may be described as thin layers of fine vegetable fibre. It is made from the following materials : — Linen and cotton rags, refuse flax and hemp, jute, esparto grass, straw, soft wood, and waste-paper. In America a considerable quantity of wool is used. The best paper is made from rags. The first object the manufacturer has in view is to cleanse, bleach, and reduce the fibre to a fine pulp with water ; and the second is to get the pulp into even sheets (of a thickness corresponding to the thickness of the paper required), to be subsequently dried, sized, and rolled. In the preiMration of materials the rags have to be sorted into linen and cotton, and each of these again into twc or three qualities and colours. This operation is performed by women and girls, who, at the same time, cut the rags into pieces about the size of the hand, and remove any buttons, hooks, eyes, or pins. The pieces are next put into a dusting machine, where they are torn to pieces with iron spikes, and the dust and dirt beaten out and removed. (Sometimes the PLANTS AND THEIR PRODUCTS. 87 rags are partially cleansed before sorting and cutting.) Next they are boiled in large revolving vessels with, water to which lime or caustic soda has been added. This process removes grease, and stains, and colouring matter. The boiled rags are now still further torn and reduced to a partial pulp in a breaking machine. This machine is so con- structed that the rags are made to pass between revolving spikes, like knife-blades, and the material is cut and torn into fine threads. Clean water is kept flowing through this machine. The half-stuff, as the torn fibre is now called, is passed into another machine, where it is bleached by a mix- ture of chloride of lime and water. After another washing the bleached half-stuff is reduced to a fine pulp in the beating engine. Various substances are now added to the pulp. (1.) China clay, or pearl-white, to make the paper more solid ; this is called loading the pulp. Loading weakens the paper, and is not used in hand-made paper, but it fills up the pores and assists the paper to take a better finish. (2.) Sizing materials. These are used for all writing and most printing papers. For machine-made paper resin and car- bonate of soda are thoroughly incorporated with the pulp, and then a solution of alum is added. (3.) Colouring matter. To give the blue tinge to white paper either cochineal and ultramarine blue, or magenta and aniline blue, are added. For blue paper ultramarine is the pigment added. For tinted paper, as a rule, aniline colours are used. Esparto grass * is treated very much like rags. It is first carefully picked over to remove any foreign matters, and then boiled in a stronger solution of caustic soda than rags. After being thus softened, it is broken and beaten to pulp, and bleached as in the case of rags. Other fibres are treated much in the same way. It would be unprofitable labour to attempt to describe the intricate machinery used in making this useful commodity ; * Imported chiefly from Algeria and other North African countries. 88 NATURAL HISTORY OBJECT LESSONS. but the principle is illustrated in the manufacture of hand- made paper. Hand-made paper is made on a very shallow siould. This mould has a bottom of wire-cloth, supported by stout wires beneath, and a movable frame. The workman dips this mould into the milk-and-water-looking pulp and takes up sufficient to form a sheet of paper of the required thickness. As the mould is lifted from the yat the water drains off through the wire cloth and a sheet of pulp is left behind. The movable frame, or deckle, is now taken off and the sheet of pulp is turned over on to a sheet of felt. The pulp adheres to the felt. A number of sheets thus made are piled on each other, with pieces of felt between each pair. When the pile is complete, the whole is subjected to great pressure to remove the water. When sufficiently dried the sheets, which resemble blotting-paper, are removed and dipped into a solution of gelatine for the purpose of sizing. They are again slightly pressed, and dried slowly c.i lines or poles. Finally, to make them smooth and glossy, they are passed between hot rollers of polished steel. Machine-made paper is made in a somewhat similar way ; but the pulp is allowed to flow out of the vat on to an endless band of wire-cloth. The water is partially drained off, and then the pulp is passed on to felt bands, and pressed between rollers, and then on to other rollers until at the end of the machine it comes out as finished paper. The water-marks are produced by patterns woven into the wire-cloth. It has been estimated that the yearly production of paper in the whole world amounts to 800,000 tons, of which one- half is used in printing. PLANTS AND THEIR PRODUCTS. 89 CHAPTER XVII, BLEACHING AND DYEING. Bleaching is the process by which substances are deprived of their natural colour, and rendered white or nearly so. Clothing made of such materials as " unbleached calico," " brown holland," and so on, on being repeatedly washed with soap and soda, and exposed in the open air to dry, become whiter and whiter until they are scarcely to be dis- tinguished from the ordinary bleached goods. This is prac- tically the old method of bleaching — a method which to some extent is still in use, especially in the bleaching of linen. The following are the chief processes in the bleaching of cotton cloth — grey cotton. 1. The pieces are sewn together, end to end, till several miles of stuflF are ready. The cloth is then singed, to remove short threads and downy pile from the surface. This is done by passing it over hot plates, or rollers. 2. The cloth is next boiled several hours under pressure with slaked lime to remove impurities, and then washed and squeezed. 3. Next it is steeped in a weak solution of acid, and then washed and squeezed again. 4. Boiled in a solution of soda-ash and resin for several hours, under pressure, and washed and squeezed again. 5. Steeped in a weak solution of chloride of lime. Washed and squeezed again. 6. Boiled in acid solution, and again washed and squeezed. 7. Opened out and squeezed between rollers placed in hot water. 8. Passed through mucilage of starch made from wheat or Indian corn.* * Other and sometimes harmful iBgredients are too often added to give a fictitious appearance of weight and bulk. 90 NATURAL HISTORY OBJECr LESSONS. 9. Dried between hot rollers. Some other minor processes follow dependent on the kind oi finish to be given. The bleaching of linen is very similar to that of cotton, but requires a repetition of some of the operations. Straw, for straw-plaiting, is first steamed and then bleached by exposure to the fumes of burning sulphur, viz., sulphurous acid gas. The bleaching of wool and silk is more simple than that of cotton and linen. It consists of two processes — scouring or cleansing, to get rid of the oily matter in wool, and the gummy matter in silk ; and bleaching, by means of sulphurous acid gas. Wool is cleansed by heating to about 90 degrees in pure soft water to wbicb some substance containing a little ammonia has been added, and rinsing in water. Silk is cleansed by boiling for -an hour in a weak solution of soap in water, and rinsing in pure water. Dyeimg is the process by which new and permanent colours are given to substances such, as cotton, woollen, linen, and silk goods. The colouring matters are derived mostly from plants, though some are obtained from the animal and mineral kingdoms. The dye-stuffs are found in all the organs of plants : thus in the madder and turmeric they are obtained from the roots; in logwood, Brazil wood, and fustic they are found in the wood ; in quercitron in the bark ; in safflower and saffron they are furnished from the flowers ; while indigo is derived from the juice of the leaves and stalks. The most important red dye-stuffs are madder, logwood, Brazil wood, cochineal, and the aniline dyes. Of the yellow dye-stuffs, quercitron and fustic are the most important, while indigo is the chief of the blue colouring matters. Of the various dye-stufl?'s a few, like indigo and the aniline dyes, are capable of giving & permanent colour when the material is simply placed in a solution of the dye. The PLANTS AND THEIR PRODUCTS. 91 finest shades of mauve, magenta, and purple may be ob- tained by placing wool, or silk fibre, in a solution of aniline dyes. But the greater number of the colouring matters may be removed by washing. Thus, if calico be dipped in madder, or flannel in cochineal solution, the colouring matter may all be removed by washing. It becomes neces- sary therefore to adopt some method oi fixing the dye to the fabric. This is effected by the use of various substances which possess a strong tendency to attach themselves to the fibres of the texture, and at the same time combine chemically with the dye-stuffs. The substances which thus form a kind of connecting link between the materials and the dye are called mordants [Fr. bitingl. Mordants are very numer- ous and they are applied in a great variety of ways. (Salts of iron, alumina, tin, and copper, are the principal.) The same mordant with different dyes produces different tints, and the different mordants produce different colours with the same dye. The more common plan of dyeing is to mordant the goods before applying the colouring stufi", but occasionally the mordant and the dye are mixed together. As one example of the more usual method, we may take the dyeing of calico black with infusion of logwood. The cloth is first passed through a hot solution of sulphate of iron (green vitriol), and then squeezed between rollers to remove the excess of mordant. Next it is passed through lime and water, and then washed to remove excess of lime. The calico is now a bufi" colour ; but pass it through an in- fusion of logwood, and it becomes an intense black. It is not necessary that the whole of the cloth should be mordanted. If the mordant be mixed into a stiff paste with British gum, it may be put on in patterns by the aid of suitable machinery. In other words, the patterns may be printed on the cloth. If the cloth thus prepared be allowed to dry, and is then passed through the dye- vat and afterwards well washed, it is found that the mordanted patterns only 92 NATURAL HISTORY OBJECT LESSONS. retain the colour. This kind of pattern dyeing is an exten- sive industry in Manchester and other " cotton towns." It is known as •' calico printing." CHAPTER XVIII. TEA, COFFEE,, AND CHOCOLATE. Tea. — The tea-tree is an evergreen bushy shrub having lance-like pointed leaves with saw-like edges. The flowers are white, with yellow stamens, and are slightly fragrant. The seeds, which are enclosed in a woody shell, are oily and covered with a hard smooth skin. The bushes are kept down by pruning to an average height of from three to five feet. The tea-shrub is probably a native of China and Japan. We can trace its cultivation in China back to the fourth century, and it was introduced into Japan early in the ninth century if not earlier, and from these two countries the leaf was exclu- sively obtained till within the last fifty years. We do not hear of the introduction of tea into England in any quantity till 1657, when its price in sovereigns was greater than it is now in shillings. Its very high price kept its use limited to the wealthy classes for many years ; now it is used habi- tually or occasionally by half the human race. In the year 1834, the tea-plant was discovered growing wild in Upper Assam, and now its cultivation, both there and on the slopes of the Himalaya and Neilgherry Moun- tains, has become an important and extensive industry. The shrub requires a warm climate, and a rich, deep and damp, but well-drained soil, to bring it to perfection. Like the coffee plant, it grows best on hill-sides. The young trees are planted in rows from four to five feet apart, num- PLANTS AND THEIR PEODTJCTS. 93 bering about two thousand trees per acre. After the fourth or fifth year an acre will yield from 240 to 320 pounds of tea. The picking commences in April, and is continued till October. The preparation of the leaves consists in drying, rolling, fermenting, and roasting. The manufacture of tea in India is somewhat less complicated than in China. The young shoots, with three or four leaves attached, are plucked with the finger and thumb, old leaves being discarded. These are placed on mats and exposed to the sun for a few hours, till they become sufficiently flaccid to bear rolling without breaking. They are next rolled with the hands on a deal table, and then thrown into a loose heap and covered with mats or carpets to allow of a slight fermentation. The leaves are now roasted for a few minutes in shallow metal pans, and then thrown quickly on the table to be rolled again while hot. This process is repeated, and finally the now black leaf is dried by exposure to the sun, or over char- coal fires. Either black or green tea may be prepared from the same leaf. If the latter is required, the process of fer- mentation is dispensed with, and the leaves are more rapidly dried and rolled. Formerly large quantities of colouring matter were used to heighten the colour, and give the tea a bright green appearance. Such coloured tea was never used by the Chinese themselves. Many different sorts of tea are imported, but those best known are Pekoe, Souchong, Congou, and Bohea, all black teas. In greens Hyson and Gunpowder are the most familiar. The youngest, and hence the smallest leaves, pro- duce the most delicate flavoured teas. The earliest pickings of all seldom leave China, they are reserved for home use and as presents for friends. A small portion is sent by caravan to Russia, and is said to fetch two guineas a pound. The main picking forms Congou, and this is the main bulk of the British imports. Pekoe and Souchong are finer and dearer 94 NATURAL HISTORY OBJECT LESSONS. kinds, the result of earlier pickings. Bohea is much coarser. Hlassa brick-tea is pressed into the form of a brick. It is prepared for use with butter and salt, and is preferred to all other kinds by the natives of Central Asia and Tibet. The infusion of tea has very little nutritive value, that is, it is not in any sense a food. It increases the respiratory action, promotes perspiration, and therefore tends to cool the body, and stimulate the brain to greater activity. China and India (Bengal and Burmah) are the chief sources of tea. From these two countries about two hundred million pounds of tea, of the total value of £11,000,000, are imported every year. Coffee. — The coffee-tree is indigenous to Abyssinia, where it still grows wild. From Abyssinia it appears to have been introduced to Arabia and Persia, in which countries coffee soon became the national beverage. The y;reat demand for its seeds has led to its cultivation in most of the tropical countries where a suitable situation can be found. Brazil, Java, Sumatra, Ceylon, Jamaica, and Arabia are the great coffee-growing countries. One species of the coffee-plant grows wild in great abundance along the whole of the Guinea coast. The common coffee-tree is an evergreen plant, with smooth shining leaves five or six inches long, resembling those of the Portugal laurel. The tree naturally grows to a height of eighteen or twenty feet ; but in cultivation is kept down by pruning to a height of about six feet. It bears small pure white flowers characterized by a rich fragrant odour ; but they quickly fade. The fruit which follows is a fleshy berry having the appearance and size of a small cherry. As it ripens it assumes a dark red colour. Each berry contains two seeds embedded in the j^ellowish pulp, and enclosed in a tough skin, called the parchment. The seeds, or " beans," which constitute the raw coffee of commerce, are curved at the back, and flat and deeply furrowed at the front. PLANTS AND THEIR PRODUCTS. 95 The cultivation of the coffee-plant requires much care. The plants begin bearing in the second year, and in the third should yield a fairly remunerative crop. The berries are ready for gathering when the skin begins to shrivel up. Immediately after picking they are taken to the " pulping " house. Here the pulp is crushed and bruised between roughened rollers, and then washed away by a stream of water. The beans are now dried in the sun, and as soon as practicable freed from the " parchment " by passing between wooden rollers, and winnowing away the broken skin. The shelled coffee is now passed along a tube perforated with holes, of regularly increasing diameter, which separate the beans into various sizes. Lastly, they are hand-picked to free from defective seeds, and packed in bags ready for export. A tree in good bearing will produce about two pounds of berries annually ; but very much depends on situation, soil, and climate. The trees grown in dry situations, such as hill-sides, yield less weight of berries, but of superior quality. In the low moist lands the yield is greater, but the quality inferior. Raw coffee seeds are tough and horny in texture, and of a greenish colour. They are entirely devoid of the aroma and taste which characterize the roasted seeds. Roasting is an operation of the greatest nicety. On its success the pleasant flavour of coffee depends. If the seeds are roasted too little the aroma is not sufficiently developed, while if roasted too much it is partially destroyed. The roasting is conducted in iron cylinders, which are made to revolve over the fire so that all the beans in turn may be exposed to the same degree of heat. The coffee beans when roasted may have three degrees of shade — reddish- brown, chestnut-brown, and dark brown. The dark brown gives the fullest, but not the most delicute flavour. Coffee should be roasted the shortest practicable time before required for use, for the roasted beans deteriorate in flavour ; and the 96 NATURAL HISTORY OBJECT LESSONS. grinding should immediately precede the making, for ground coffee rapidly loses its aroma. If coffee must be kept in its ground state a clean stoppered bottle answers best. Ground coffee in the past has been subject to extensive adulterations, and this may partially account for the declin- ing popularity of this beverage in Great Britain. Roasted and ground roots of dandelion, carrot, parsnip, beet, corn, peas, beans, acorns, &c., are among the adulterating sub- stances. The mixture of chicory* with coffee can scarcely be looked upon as an adulteration, for many persons prefer the mixture to the pure coffee. It gives to the decoction additional colour, bitterness, and body. The admixture of chicory with coffee is readily detected by placing a few grains in cold water. Chicory betrays itself by the deep brown stains in the water, while coffee is insoluble. It is a curious fact that cocoa, coffee, and tea were all introduced into this country within a few years of each other. Cocoa was brought from South America via Spain, coffee from Arabia via Constantinople, and tea from China by the Dutch. The first coffee-house was opened in London in 1652, and coffee soon became a favourite beverage. The total annual world's produce of coffee berries is esti- mated at about 500,000 tons, of which 70,000 tons, valued at £5,000,000, are received in this country. Cocoa, or Cacao. — The cacao-tree, Theobroma f cacao, is a small evergreen tree which grows in the West Indies, in Central America, and in the tropical parts of South America. It abounds in the forests of Demerara. The tree requires careful cultivation. It needs a rich soil and humid climate, and protection from cold winds and violent storms. This * The chicory or succory plant is a native of our own country. It grows on chalky soils, and by the dusty roadside. It is known hy its large and hright blue colours, and toothed leaves. It is cultivated to some extent in Yorkshire, but its roots— for roasting and grinding — are mainly imported from Belgium and other continental countries. t Viz. food for the gods. PLANTS AND THEIE PRODUCTS. 97 protection is given by planting other trees for the purpose. The cacao-tree begins to bear about the sixth year. Buds, flowers, and fruit in all stages of growth are to be found on the same tree, hence ripe fruit may at all times be collected ; but the chief harvests are in June and December. The flowers grow in clusters on the trunk and main branches. The pods, in which the seeds are enclosed, are from seven to ten inches long, and three or four inches in diameter. They are hard and tough and ridged longitudinally, and contain from twenty to forty seeds attached to a central core, and are embedded in a mealy piakish-white pulp. The seeds, or nuts (constituting the cocoa-beans of com- merce), are enclosed in a thin, hard, and brittle shell. When removed from the pods they are put into boxes, or buried in the ground for about two days, during which time they fer- ment. Great care must be taken not to allow them to heat too much, or the flavour would be spoiled. They are next dried in the sun, roasted and crushed, and then winnowed and picked over by hand to remove broken shells and any mouldy or discoloured fragments. The broken pieces of kernel are called nibs. Sometimes the kernels are ground into a fine meal, of which a paste is made. This paste is allowed to harden, when it is cut into thin slices forming flaked cocoa. When the oil has been extracted before grinding to powder, the preparation is called essence of cocoa, or soluble cocoa. Nibs require long boiling, but soluble cocoa can be prepared by merely pouring on boiling water and stirring. Soluble cocoa formed into a paste, with the addition of sugar and a little flavouring matter, is called chocolate. Cocoa is brought chiefly from the West India Islands, Brazil, and Ecuador ; and, in a manufactured state, from France and Holland. In all about 10,000 tons, valued at about three-fourths of a million pounds, are annually im- ported. 98 NATURAL HISrOEY OBJECT LESSONS. CHAPTER XIX, SPICES. Cloves.* — The trees and shrubs of the myrtle tribe are generally aromatic, and many of them yield a pungent vola- tile oil. They are mostly tropical, or sub-tropical plants. The unexpanded flower-buds of one tree of this natural order, a native of the Moluccas, or Spice Islands, constitute the cloves of commerce. The tree is a beautiful evergreen, bearing large oblong leaves, and a profusion of crimson flowers. The flower-buds are at first of a pale yellow colour, but they change gradually to green, and then to bright red. As soon as the latter colour is developed the flower-buds are ready for plucking and drying. The clove is now grown in the West India Islands, and in Java and Sumatra in the East Indies. It is only within a very limited range of climate, however, that the clove acquires its full aromatic flavour. Every part of the clove-tree abounds with aromatic oil ; but it is most plentiful in the unexpanded flower-buds, from which 18 per cent, of oil may be extracted. The clove of commerce is of a deep brown colour, and possesses a pungent taste, and powerfully fragrant odour. Allspice. — From another tree of the myrtle tribe, a native of the West Indies, allspice, pimento, or Jamaica pepper, is obtained. Allspice is the dried berry ; it is so called because it is considered to have the flavour of cloves, cinnamon, and nutmeg combined. It is mildly pungent, and agreeably aromatic. Cinnamon is the dried inner bark of an evergreen shruh belonging to the same tribe as the English bay-tree. It is almost exclusively a product of Ceylon, whence about seven * So called from the French, word clou (a nail), on account of its resem- blance to a nail. PLANTS AND THEIR PRODUCTS. 99 hundred tons are imported annually. The bark is taken from the twigs of eighteen months' or two years' growth, cut into lengths of about a foot, and then the outer and middle layers of bark are removed by scraping. The smaller pieces are then placed beside the larger, and the whole dried in the sun and packed in bundles for exportation. The Nutmeg was an article of commerce in Europe long before anything was known of the species or habitat of the tree from which it was obtained. It is the seed of an evergreen tree which grows wild in the Moluccas or Spice Islands, especially on three small islands called Banda Islands. On these islands nutmeg trees are now cultivated ; but large plantations are also to be found in Sumatra, and in India. In Banda the trees are planted under the shade of lofty canary trees. Here the shade, the light volcanic soil, and the excessive moisture exactly suit the nutmeg. The trees blossom and bear fruit all the year round, but the chief harvest is in the later months of the year. The ripe fruit is pear-shaped, but in size and colour it resembles the peach. The fleshy covering of the " stone " or " nut " is about half an inch thick. This bursts at the sides, splits into two halves like the nectarine, and exposes a shining black nut enveloped in a leafy net- work of a brilliant red colour. This network is carefully stripped off' and dried. It then forms the mace of commerce. The nut consists of a thin hard shell and a kernel. The shell is considerably harder than that of the filbert, and, before drying, could not be broken without injuring the kernel, which is the nutmeg itself. The nuts are dried in the sun, or in a drying-house, until the kernels shrink so much that on being shaken they rattle within the shell. The latter are now broken with wooden mallets on flat boards, and the nutmegs picked out and sorted. The inferior kernels are set aside for the extraction of the oil called " oil of mace ; " the finer kernels are rubbed over 100 NATURAL HISTORY OBJECT LESSONS. with dry lime, and packed for export. The yearly imports of nutmegs into the United Kingdom exceed half a million pounds, and of mace sixty thousand pounds. Ginger is the rhizome, or underground stem, of a reed- like plant growing to a height of three or four feet. It is grown in most tropical countries, but especially in the East and West Indies. That brought from Jamaica is considered the best. The ginger of commerce is classed as black and white — the coated and the uncoated. For the first kind the irregular palmate rhizomes are simply washed and dried in the sun. For the second kind the pieces are washed, scraped, and sun-dried, and then often bleached by the use of sulphur fumes, or chloride of lime. The whitewashed appearance it presents is due to a coat of whitewash applied ostensibly to give the ginger a better appearance, but more often to hide an inferior article. The properties of ginger are very marked. It has a pun- gent aromatic odour, and a hot biting taste. It breaks with a short mealy fracture, and presents on the broken surface numerous short bristly fibres. It is used as a spice or con- diment, and occasionally in medicine. " Preserved ginger " is an agreeable sweetmeat, the young rhizomes preserved in syrup being considered a great delicacy. Our chief sources of supply are India and the West India Islands. CHAPTER XX. OPIUM, QUININE, AND CAMPHOR. Opium is the dried milky piece obtained from the seed capsule of the opium-poppy. This plant is grown chiefly in Asia Minor, India, and China. The poppy grows freely in PLANTS AND THEIR PEODUCTS. 101 temperate climates, but the yield of opium is insufficient to make its cultivation profitable. The species of poppy grown, the method of cultivation, and the quality of the opium produced vary very much in different countries. In Asia Minor there are three sowings made in the year, from Octo- ber to March, so that the crops may come in succession. The first crop is usually the most profitable. The plants bloom from May to July, according to the climate ; the petals of the flowers fall in a few hours, and the capsules grow so rapidly that the opium is ready for collection in from ten to fourteen days. It is always collected by hand. Shallow incisions are made in the capsules in the afternoon and even- ing, and the juice which exudes is collected the next morn- ing by scraping with a knife, and transferring to a leaf. When one leaf is filled, another leaf is pressed on the top, and the collection is placed in the shade for a few days to dry.* The whole of the collection must be made in a few days, while the capsules are in a condition to discharge their juice. When the pieces are sufficiently dry they are packed in cotton bags, sealed, and carried to Smyrna or some other port. Here it is carefully examined, and sorted according to quality, before exportation. Turkey opium is generally of superior quality, and as such is used principally for medi- cine in this country. The production of opium in India is a Government mono- poly. It is open to every one to cultivate the poppy, but the cultivator is compelled by law to sell the opium to the Government at a price fixed by the agent beforehand. The usual price paid by the Government is about Ss. 6d. per lb. ; but the selling price is quite three times that amount. In the valley of the Ganges nearly a million acres are under poppy cultivation. The seed of the poppy is valuable. It yields from 35 to 42 per cent, of oil. The greater portion of the opium produced in India is " In India the juice is collected in earthenware vessels. 102 NATURAL HISTORY OBJECT LESSONS. purchased by the Chinese ; and notwithstanding this, a still larger amount is produced in China, and the cultivation of the poppy is still making rapid strides in that country. Opium is also a product in Persia, Egypt, and some other countries. The chief value of opium is as a medicine to relieve pain, to allay irritation of the nervous system, and to produce sleep. Morphia, or morphine, is the active principle, and the quality of the opium is judged by the quantity of this sub- stance it contains. Laudanum, a crude preparation of opium in spirits of wine, is the form in which opium is most largely used. It is poisonous, but, like many other poisons, its habitual use seems to destroy much of its eflPects, so that the dose has to be constantly increased. The habit of taking opium to relieve pain, or produce sleep, is difficult to break off. Much opium is used in medicine, but far greater quantities are consumed in chewing and smoking. Opium chewing is chiefly practised in India, Persia, and Asia Minor ; opium smoking is more prevalent in China. It is estimated that nearly 10 per cent, of the population of India are habitual opium chewers, and nearly 25 per cent, of the Chinese are opium smokers. Indian opium is more highly prized by the Chinese for smoking than the produce of their own country. Opium chewing and smoking seems to be very much like smoking tobacco, and, used in moderation, it is said to be no more injurious than the latter practice. Carried to excess, it is certain ruin to mind and body. Opium for use in this country is imported mainly from Turkey. Peruvian Bark — from which we obtain one of the most valuable medicines, Quinine — is taken from the cinchona, an evergreen tree, which grows wild in the dense forests of the mountainous regions of the tropical Andes. It is usually found at heights varying from 2,000 to 8,000 feet. The trees grow either isolated or in small clumps, and the work- PLANTS AND THEIR PRODUCl'S. 103 men in their search have to cut their way through almost every step they take in the forest. When a tree is disco- vered it is cut down, and the whole bark of the stem and branches is secured. The thinner bark of the branches, which makes the rolled bark, is merely dried in the sun, when it naturally takes the form of hollow cylinders. The squares from the trunk are subjected during the process of drying to great pressure. They are alternately dried and pressed until in a fit state for the market. The bark is now carefully tied in bundles, and sown up in woollen canvas, to be carried by the men out of the forests. When they reach the town depots the bundles are opened and the bark sorted, and repacked in rough chests covered with hides for exportation. The enormous consumption of these barks, and the waste- ful and reckless manner in which the trees are destroyed to procure them, led to the fear that the supply would soon become exhausted. Efforts have therefore been made, and with considerable success, to cultivate the tree in Southern India, Ceylon, British Burmah, and on the southern slopes of the Himalayas. In the Neilgherry plantations alone several million cinchona trees are now under cultivation. The preparation from the chinfjhona bark most extensively employed in medicine is known as Quinine (Sulphate of Quinine). The discovery and the use of quinine made quite an epoch in the history of medicine. Besides being a spe- cific in ague and fevers, it is used as a tonic to brace up the nervous system, and to recruit the general health. Peruvian bark is obtained chiefly from South America, and from Ceylon. Camphor. — Of the many secretions stored up in plants camphor is one of the most important. It may be obtained in small quantities from the roots of thyme and sage; but the main supply is derived from two trees, the first, the camphor laurel, growing principally in China and Japan, and most abundantly in the island of Formosa ; the second, 104 NATURAL HISTORY OBJECT LESSONS. a tree belonging to the same family as the limes, a native of Sumatra and Borneo and the Malay peninsula. The camphor laurel is about the size of our English oak. Every part of the tree is strong'ly impregnated with cam- phor, but the roots yield the greatest quantity. These are cut in pieces and placed in an iron retort, with an earthen or wooden top. In the hollow of the top, or lid, hay or straw is fastened across, so as to form bars or cords, and the whole is made air-tight by means of hempen packing. When the retort gets hot, the camphor escapes as a vapour, and is con- densed on the straw. The camphor thus collected is of a brownish-white colour, and needs to be purified by a second distillation. In China this is efiected by placing alternate layers of camphor and dry earth in a copper still, and cover- ing the whole with a vessel made of straw, but covered on the outside with clay. On heating, the camphor is again vapourised, and then collected on the straw, where it crystal- lises. From the trees in the Sumatra, Borneo, and the Malay peninsula, camphor is obtained in pure crystalline masses without the trouble of distillation. It is found solid in cavities or fissures, sometimes a foot and a half long, within the trunk. These cavities, however, cannot be discovered without sacrificing the trees. The trees are cut down and then split by means of wedges. Often, however, the tree is hacked and hewn to pieces without avail. The cavities are filled with a black pitch-like substance of no value. Camphor has a penetrating and aromatic odour, and a strong unpleasant taste. It is very sparingly soluble in water, to which, however, it imparts its peculiar odour and taste. It is soluble in alcohol and in oil, and 100 parts of spirit will dissolve 120 parts of camphor ; the solution forms " spirits of camphor." If this solution be poured into water the camphor reappears in white fiakes. Camphor is so tough that it is reduced to powder with great difficulty. The addi- PLANTS AND THEIR PRODUCTS. 105 tion of a few drops of oil or spirit, however, destroys the toughness. It melts at a moderate temperature, but passes off at once as vapour. It burns readily, even when floating on water, and gives off quantities of smoke. Camphor is used as a medicine,* and it enters largely into the composition of varnishes used by painters. Small insects cannot endure the powerful scent of camphor, and it is used, therefore, for the protection of dried specimens in cabinets and museums, and for the preservation of furs and woollen fabrics from the depredations of moths. CHAPTER XXI. MISCELLANEOUS ARTICLES— INDIGO, OAK-GALLS, CORK TIMBER, FRUITS, LIQUORICE. Indtgo. — The beautiful blue vegetable dye known as indigo may be derived from the leaves of several plants ; but the indigo of commerce is prepared mainly from a plant of the pea and bean tribe, which is cultivated for the purpose in Bengal. The Indigofera tinctoria is a herbaceous plant, grow- ing from three to five feet in height. The indigo-yielding principle resides chiefly in the leaves, and these are most gorged just as the flowers are beginning to open in June and July, when the indigo harvest commences. The plants are cut down and tied in small bundles, and conveyed at once to the factory. This consists of two ranges of large vats or tanks, twenty feet square and five feet deep. One range is at a lower level than the other. The bundles are placed in water in the vats of the upper range and kept * " Camjilior balls," or a few drops of spirits of camphor on sugar, if taken in time, will often wiird off a cold. Camphorated spirit is alto a good remedy for chilhlains and burns when the skin is not broken. 106 NATURAL HISTORY OBJECT LESSONS. down by cross-bars. Fermentation soon sets in, which is allowed to continue for from nine to fourteen hours, according to the temperature. When the process has reached a certain point, of which the manufacturer judges by experience, the liquid assumes a fine yellow colour. It is then drawn ofi' into the lower tanks, and lashed furiously with long bamboos to expose fresh surfaces to the air. The liquid gradually assumes a green colour, and broad flakes of indigo begin to appear and sink to the bottom. When the process is com- plete, and the indigo all settled at the bottom, the clear liquid is run ofi: The indigo is then taken and raised to the boil- ing point. It is now allowed to rest for a day, then boiled for three or four hours, and lastly drained on calico, and pressed and dried. Bengal indigo of good quality is of an intense violet-blue colour ; it breaks easily, and the fracture shows a peculiar coppery lustre. Indigo is the most important of the colouring matters used in dyeing and printing calico. Bengal and Madras are the chief sources of supply. Oak- Galls. — Guided by a remarkable instinct, insects deposit their eggs in such positions and places, that when the young grubs appear they may find a sufficient supply of suitable food. The females of one species of fly known by the name of Cynips, or Gall-flies, deposit their eggs within the leaves and young shoots, and even the acorns and cat- kins of the different varieties of the oak-tree. The ovipositor, or egg depositor, of this insect consists of three lanceolate plates, arranged to form a triangular tube, which pierces the tissues of the plant, and through which the eggs are con- veyed to their destination. The wound made by the ovipo- sitor sets up a kind of local irritation and inflammation; around this a swelling takes place, and very soon the eggs are within a globular fleshy chamber, the walls of which form a storehouse of food for the future grubs. These excres- PLANTS AND THEIR PE0DTJCT8. 107 cences vary in form, size, and structure, according to the species of gall-fly producing them. The " oak-apples" found on the leaves of the English oak are smooth and round, and about the size of large marbles. The "nut-galls" of com- merce are formed on the young twigs of a small oak which flourishes wild in Asia Minor, and in other countries border- ing the Mediterranean. The best " Aleppo-galls " are hard brittle balls, about half an inch or less in diameter, ridged and warty on the upper half, and light brown to greenish- yellow within. The galls are gathered before the full-grown larvae have tunnelled a way of escape. In this state they are termed blue galls. The white galls, viz., those gathered after the escape of the insect, are lighter in colour, less in weight, and altogether inferior in quality to the blue galls. Commercial gall-nuts yield from one-fourth to three- fourths of their weight of tannin, and about two per cent, of gallic-acid. Tannin is present in the bark of many trees, especially in- that of the oak ; it is used for tanning leather. The tannin of gall-nuts is used to some extent on the Continent for tanning purposes. Q-allic-acid, as we have seen, exists ready formed in small quantities in gall-nuts. It may, however, be readily obtained from tannin by allowing an infusion of gall-nuts to stand in a warm place for some weeks exposed to the air. Grallic-acid is an essential ingredient in the manufacture of black ink, and the first process in the manufacture is the fermentation of the powdered nut-galls to produce gallic-acid. Cork. — The layer of tissue found immediately beneath the epidermis we have described as consisting of cellular tissue. This layer is usually thin ; but in the bark of one species of oak it attains to a remarkable thickness. On this account the tree is named the cork-oak. The cork-oak grows wild in the countries bordering on the Mediterranean Sea, but more especially in Spain and Algeria. When about five years old the corky layer begins to make 108 NATURAL HISTORY OBJECT LESSONS. very rapid growth, and when the tree has attained the age of from fifteen to twenty years it is ready for its first strip- ping. The operation of barking does no harm to the tree, provided the inner bark is not injured in the process. The stripping is done in July and August. Incisions are made in the bark all round the tree at regular intervals, then a longitudinal cut is made from top to bottom, and the bark is detached in cylindrical pieces. The first stripping is rough and woody in texture. It is used for ornamentation under the name of virgin cork. The second stripping, which is made from eight to ten years after the first, is also coarse in texture ; but the quality of the cork improves with each successive stripping, until the trunk has been denuded of its covering for the eighth or ninth time. When the cork has been removed the outer surface is scraped and cleaned ; it is then ready for charring and flat- tening. The flattening is done by pressure on a flat surface. It is then dried and charred over a brisk fire in what is called the " burning yard." The burning must be managed with care, else the cork is burned and blackened. The char- ring causes the bark to shrink, and the pores to close up, rendering the cork impervious to fluids. Cork possesses a combination of properties which peculiarly fit it for many and diverse uses, for many of which it alone is found applicable. Because of its compressibility, elasticity, and practical imperviousness to air and water, it is used as stoppers for bottles and barrels. Because of its specific lightness, combined with strength and durability, it is used in the construction of life-buoys, cork jackets, life-boats, and other life-saving apparatus. Because of its specific light- ness, softness, and non-conductive properties, it is used for hat-linings, inner soles of shoes, &c. The chips and cuttings are not wasted ; they are ground up and mixed with india-rubber to form kamptulicon floor- cloth ; or they are ground and mixed with linseed oil, and PLANTS AND THEIR PRODUCTS. 109 spread over a canvas backing to form linoleum. Our large supplies of cork are obtained from Portugal, France, and Spain. Timber. — The word timber is used in a twofold sense. It is applied to such, trunks of trees as are fit, from their size and quality, to be sawn into planks for building and other purposes. The planks themselves are also often called timber. Although not the strongest or the most durable, the tim- ber obtained from the great family of conejaearing trees — the firs and pines — is the most valuable m an economic sense because it is plentiful, and therefore cheap ; and it is easily worked. In Sweden and Norway, in Russia and Ger- many, and especially in Canada, there are vast pine forests from which our main supply of this timber is drawn ; but there are also valuable forests of these trees on the slopes of the Alps and Pyrenees, and in Scotland. The chief timber-trees in these forests are the Scotch fir, the spruce fir, the silver fir, the "Weymouth pine, and the larch. The Scotch fir produces the most valuable timber. It is called by various names — Riga fir, red pine, and red deal. It is obtained chiefly, though not exclusively, from Sweden, Norway, and Russia. The Weymouth pine is the great pine of the Canadian forests. Its timber is the yellow pine of American commerce. It is not so flexible, durable, or elastic as the red pine ; but it is more easily worked. The timber of the spruce and silver firs is called white deal, or white Norway, Christiana, and Dantzio deal. White deal does not readily warp, and is useful for flooring. The spruce fir is much used whole for scaffolding, ladders, small masts, mining timber, &c. The wood of the larch is noted for its durability. First among the hard-wood timbers is the common British oak. In strength and durability it surpasses all other woods. Oak timber is imported from America, but it is much in- 110 NATURAL HISTORY OBJECT LESSONS. ferior in quality to the English oak. Other valuable hard woods of this country are the ash — much used by coach- builders and wheelwrights, and for making handles for tools ; the elm, a timber noted for its durability under water ; and the beech, used in making furniture. Of the hard woods imported, teak — "the king of the Indian timber- trees " — is the best. Mahogany from Central America is much used in the manufacture of furniture. The total value of timber of all sorts imported into Great Britain in the jear 1883 was nearly £18,000,000. The largest supplies are drawn from Canada, the United States, Russia, Sweden, and Germany. Fruits. — The fig-tree is probably a native of Asia Minor and Syria, but it now grows wild in most of the countries bordering the Mediterranean. The bush or tree rarely exceeds 18 or 20 feet in height, which bears, in the cultivated varieties, broad, rough, and deeply-lobed leaves. Judging from the many allusions to the fig in the Bible, this fruit was probably one of the earliest objects of cultiva*^ion. The trees bear two crops annually : the first, or summer crop, from the buds of the preceding year ; and the second, or autumn crop, from the spring buds. When ripe the fruit is picked, and spread out in the sun to dry. Those of the better quality are pulled and stretched during the drying process. When ready they are neatly packed in boxes for export. From six to seven thousand tons are brought into this country every year, four-fifths of which come from Asia Minor. The best kinds are shipped at Smyrna, where the fig trade forms one of the chief industries of the people. Figs form a considerable part of the food of the people of Western Asia, both in a fresh and dried state. The inferior sorts are sometimes mashed and made into cakes, to serve as a substitute for bread. - The Orange. — The orange-tree is probably a native of India and China. It is still found growing wild in the PLANTS AND THEIE PRODUCTS 111 jungles of Northern India. It is abundantly cultivated in Spain and Portugal, Sicily, the Azores, Jamaica, and Florida ; and to a less extent in almost every other tropical and sub- tropical country. By far the largest quantity of oranges are imported from Spain. The tree is evergreen, and of medium size, seldom rising above 25 feet in height. The flowers, which are of a delicate white colour, appear in sum- mer, but the fruit is not ready for picking till the following year. Hence, flowers and fruit in various stages may be seen on the trees at the same time. At ten years old the orange-tree will produce 1,000 to 1,600 good oranges, and when full-grown 7,000 or 8,000, and occasionally a large tree will yield twice as many. There are numerous varieties of the orange ; the best of the sweet oranges are the St. Michael's and the Maltese. The Seville, or bitter orange, is grown in large quantities in Spain, and imported into this country and the United States for making marmalade. The rind is made into candied orange-peel. The leaf, the flower, and the rind of the fruit of the orange-tree all yield volatile oils. The scent of eau de Cologne is due chiefly to oil distilled from the orange-flower. The rind of the Bergamot orange yields essence of bergamoi, largely used in perfumery. The Lemon. — The lemon, orange, and citron-trees belong to the same tribe of plants. The lemon is cultivated exten- sively in the south of Europe. Citric acid, obtained from the juice of the lemon, is used extensively in the arts and in medicine. Essence of lemon, used for flavouring and in perfumery, is distilled from the peel. The peel is also candied. Grapes are grown in immense quantities in France, Spain, Portugal, and Italy, and in some parts of Germany, mainly for the manufacture of various wines. The greatest wine- producing country in Europe is France. The average yield 112 NATURAL HISTORY OBJECT LESSONS. from 1880 to 1884 was 700,000,000 gallons. Italy stands next to France in the quantity of wine produced. Raisins are dried grapes. The fruit, when fully ripe, is scalded in a caustic saline ley (made by passing water through the ashes of burnl vine prunings), and then dried in the sun for about a fortnight. Muscatel raisins are dried on the vine, and not scalded. The stalks of the bunches of grapes are partly cut through, and the leaves are removed to allow the sun to have full play on the fruit. The beautiful small sultana raisins having no seeds are produced in Turkey. The small grapes known as currants are produced in the Corin- thian Islands. The bunches of fruit are about three inches long, anfi the grapes are about as large as peas. LiQUOKicE, viz. sweet root, is obtained from the root of a perennial plant with herbaceous stalks and purplish flowers. It is indigenous to the more southern countries of Europe, but has been cultivated in this country, particularly in York- shire, during the past three hundred years. The root is long and succulent, and tough and flexible. Its colour on the outside is greyish brown, but yellowish within. It possesses a sweet, gummy, and slightly acid taste. It is sliced and lightly boiled, and the liquor is strained, and the water evaporated till the residue is of proper consistency. This constitutes the liquorice. In Spain and Italy it is formed into rolls, and packed in bay-leaves. The chief use of liquorice is to give colour and body to "porter." Italy and Turkey are the chief sources of supply. ANIMALS AND THEIE USES. H ANIMALS AND THEIR USES. CHAPTER XXII. CLASSIFICATION OF ANIMALS. Systematic arrangement, that is, clamfication, is the fun- damental basis of the study of Natural Science. It would be impossible to study the structure and habits of the count- less animals which people water, earth, air, and sky, their mutual relationships, and their relative importance in the eco- nomy of nature, without first reducing them to something like order. At first sight classification may appear an easy task. No one could mistake a cat for a cow, a bird for a snake, a frog for a fish, or a spider for an oyster. But in reality the task of classification is one of great difficulty. It is easy enough to distinguish the typical animals of one group from the typical animals of th e next group ; but there exist pretty nearly always animals which partake of the characters of both groups — "con- necting-links " they have been called — which may lay claim to belong to either group. The typical character of one group in certain animals seems, as it were, to shade off, and merge into, the typical character of the next group. Thus, one typical character in the Quadrumana* is the presence of four hands, each having four fingers, with flat nails re- sembling our own, and an opposable thumb. Now in the Marmozets, a family of American monkeys, the thumbs of the anterior hands are scarcely at all opposable ; and the * L. quatunr and manus, four liands. 116 NATURAL HISTORY OBJECT LESSONS. nails of all the fingers, thumbs excepted, are claws like those of the cat. Again, in the Lemur-like animals, the nails are all flat, except that of the first finger of the hinder hand ; and all the thumbs are well developed and opposable to the other fingers ; yet in form and appearance these animals look more like squirrels, foxes, cats, &c., than monkeys, and for such they are often mistaken. Writing of one of these creatures, the Rev. W. C. Thomson says : " It was the very epitome of zoology ; of the size and colour of a rat, it had the tail of a squirrel, the face of a fox, the mem- branous ears of the bat, the eyes of an owl, the long, slender fingers of a lean old man who habitually eats down his nails, and all the mirthfulness and agility of a diminutive monkey." Instances might be multiplied out of number of animals which mark the transition, by an almost insensible grada- tion, from one group to another. The best classification must, therefore, be but an artificial and arbitrary arrange- ment, and of necessity very imperfect. Yet, in spite of this, classification is a necessity, because it shortens and simplifies the labour of the student. A know- ledge of a typical member of a group gives us a fair insight into the special characters of the whole group ; or, con- versely, an acquaintance with the general characters of a group is a passport to an immense amount of information about every individual of the group. Thus, for instance, take the serpent-tribe. We may say of the numerous kinds of serpents that they all have certain characters in common ; and that no other known animal possesses the same combi- nation of characters. They all possess a " backbone " com- posed of numerous -pieces jointed together by ball-and-socket joints. These bones form the walls of a channel through which the great nerve passes. The channel opens out at one end to form a cavity to hold the brain. Numerous ribs are jointed to the pieces of the backbone, but there are no limbs. Compared with that of beasts and birds the blood is ANIMALS AND THEIR USES. 117 cold. The heart has three cavities. The upper as well as the lower jaw is movable, and the jaw bones are not jointed to other bones, but simply held in their places by the elastic skin. The tongue is thin and forked, and is used only as an organ of touch. The body is covered with scales, most of which are fixed in front only, and can be raised at will ; and in such a way that their points are directed backwards ; and, as we shall show later on, it is by means of these scales that the animal glides forward. Now these characters being common to the whole group, are of course found in every individual member of the group. Again, a description of the structure and habits of the domestic cat will serve equally well, with slight variations, for the tiger, leopard, panther, and numerous other cat-like animals. In like man- ner, a description of the teeth of a rabbit, or the stomach of a cow, will apply equally well to a host of other animals, and so on. From the foregoing the teacher will note the advantages to be derived from arranging " object lessons " in Natural History on a definite system. The first step in classification is to distinguish one animal from another hy diSevences in form and sti-uciure ; and the second is to collect into groups those whose differences are small. Animals of the same kind, that is, of the same stock, con stitute a species. The term is usually applied to animals which produce others like unto themselves. The offspring of a cat is always a cat, and the young of the tiger is always a tiger. So cats and tigers form distinct species. But there are various kinds of cats, and various kinds of tigers, and so we have varieties of the same species. Again, certain species of animals strikingly resemble each other in structure and habits, but differ in minor particulars ; thus the cats, the tigers, the lions, and the leopards are very much alike, and we classify these species together to form a s — the genus Felis. Resemblances less marked between 118 NATURAL HISTORY OBJECT LESSONS. genera cause them to be grouped as families. Thus we have the genus felis, sometimes called the cats proper, together with another genus, the hycenas, forming the cat-family. [The terms sub-family and tribe are often used as synonymous with genus.] There are resemblances between the cat-family, the dog-family, the bear-family, the weasel-family, and others, sufficient for the whole to be grouped in one order — the order Carnivora, or flesh-eating animals. Orders, again, are grouped together to form classes. Animals which suckle their young, including some eleven orders, are grouped as Mammals, Birds form a second class. Reptiles a third, and Fishes a fourth class. Now all the animals in these four classes agree in one respect — they all possess a jointed back- bone. Other animals, such as snails and slugs, insects, spiders, worms, &c., have no backbone. Hence all animals may be classed in one of two grand divisions or sub-kingdoms — the Vertebrata* and Invertebrata. In the very general sketch which follows we shall direct attention to typical animals, and of these such only as will probably be useful for " lessons," leaving the student who desires for information about the less known animals to con- sult some such popular " Natural History " as that already referred to.f CHAPTER XXIII. CLASSIFICATION.— VERTEBRATA I. The animal kingdom comprises two great divisions, or sub-kingdoms — the Vertebrata and Invertebrata — dis- tinguished by the presence or absence of a jointed backbone, or vertebral column, as the chief element in an internal skeleton. * Latin vertebra from rertere to turn, so called because the separate bones are so jointed as to possess a certain power of turniiig on each other, t r'age 5. ANIMALS AND THEIR USES. 119 In addition to this internal skeleton the Vertebrates possess in common a hrain and a spinal cord protected by the skele- ton ; a heart divided into chambers, and red blood : and they all have an external covering called the skin. The sub-kingdom, Vertebrata, is subdivided into four great classes — Mammals, Birds, Reptiles, and Fishes ; and the animals included in each of these classes possess certain cha- racters in common which, as it were, bind them together. Mammals feed their young with milk formed in their own bodies ; the heart is divided into four chambers ; the blood is warm ; and the skin, except in one tribe, has a covering of hair. Birds lay eggs, from which the young are hatched ; the heart is divided inio four chambers ; the blood is warm ; and the skin is covered with, feathers. Reptiles lay eggs ; the heart has three chambers ; the blood is cold; and the skin is either naked or covered with scales or plates. Fishes lay eggs ; the heart has two chambers ; the blood is cold; and the skin is covered with scales. The Mammals are divided into orders : — 1. BiMANA, viz., two-handed. — This embraces one species only, consisting of the various races of men. Structurally man is separated from the brute creation by his erect stature, and by the possession of a pair of perfect hands. It is in intelligence, however, that the divergence is greatest. Blessed with "an intellect capable of indefinite improve- ment, man exhibits but little of that instinct which guides the operations of the lower animals. His knowledge is the result of observation, and is matured by thought ; his power of speech and the capability of writing are faculties entirely his own, whereby he can communicate his ideas and transmit to posterity the results of his experience. By no means highly gifted as relates to his bodily strength, his swiftness is very far inferior to that of most animals of his size. Pos- 120 NATURAL HISTORY OBJECT LESSON'S. sessing neither strength of jaw nor canine fangs, he is des- titute of offensive weapons ; and his body being not even clothed with hair, few creatures are, in this respect, left so utterly defenceless ; nay, in addition to these disadvantages, he is, of all animals, the longest in acquiring even that strength which is necessary for the supply of his simplest wants ; and yet this very feebleness is to him an advantage, compelling him to have recourse to that intelligence with which he has been so highly endowed. Absolutely depen- dent upon parental care for his support, he must necessarily derive from that source the education of his intellect, as well as of his physical powers, and hence is established an attach- ment as durable as it is sacred. The very length of his pupilage necessarily gives birth to habits of family subordi- nation, which ultimately lay the foundation of all social order, and tend to multiply indefinitely the advantages derivable from that mutual co-operation whereby he has suc- ceeded in subjecting or in repelling the attacks of inferior animals — in clothing himself so as to defy the inclemencies even of the most rigorous climate, and spreading his race over the surface of the earth." * 2. QuADRUMANA. — The typical members of this order are all characterized by the possession of four hand-like feet. Each of these so-called hands has long, flexible, prehensile fingers, and a short, opposable thumb. Advantage is taken of the presence or absence of certain striking, but minor cha- racters, to divide the Quadrumana into groups. These cha- racters are the tails, cheek-pouches, viz. comfortable pockets within the mouth where food can be kept till the animal is ready to devour it ; and callosities, viz., patches of hardened skin destitute of hair, on which the animal sits. The man- shaped monkeys, or apes, such as the gorilla and chimpanzee, have neither tails, cheek-pouches, nor callosities, and their fore limbs are much longer than the hinder. The baboons * Professor Eymer Jones. ANIMALS AND THEIR USES. 121 have short tails, cheek-pouches, and callosities. The mon- keys proper are marked by callosities, and most of them have cheek-pouches and long tails. The New World monkey& differ from the monkeys of the Old World in having the openings of the nostrils placed on the sides of the nose instead of at the end, and many of them have prehensile tails. 3. Cheiroptera. — The word cheiroptera means " wing- handed," and the animals included in this order are so called because the hands are developed into wings. The bones of the fingers are greatly lengthened, and the skin is extended from the body and spread over them in a thin membrane, as the silk is spread over the ribs of an umbrella. The membrane extends backwards to the hind legs and the tail ; these organs forming additional supports to the wing struc- ture. This order includes all the hats. 4. Carnivora. — This order includes a large number of animals, presenting considerable diversity of structure ; but they all agree in being flesh-eaters. It includes (i.) those which walk on their toes, viz., the cat, dog, and weasel fa- milies (digitigrades) ; (ii.) those which walk on the soles of the feet, Ariz., the bear, racoon, glutton, and badger families (plantigrades) ; (iii.) those which live partly in water and partly on land, viz., the seals and walruses. 5. Insectivora. — The more common animals which are classed as insect-eaters are the shrews, hedgehogs, and moles. This name has been given them because they feed mostly on insects, their teeth being specially adapted for crushing the hard coverings of beetles, locusts, &c. Other animals, how- ever, such as many of the bats, feed on insects. 6. EoDENTiA. — The rodents, or gnawing animals, are so called from the peculiar structure and development of the incisor teeth, which are formed for the purpose of gnawing. The order includes a vast number of animals, probably one- third of all the known mammals ; but none of them attain to a large size. The chief gnawers found in our own country 122 NATURAL HISTORY OBJECT LESSONS. are the hares, rabbits, squirrels, voles, rats, and mice. The most common of the foreign members are the beavers, lem- mings, hamsters, porcupines, guinea-pigs, prairie-dogs, and marmots. 7. Edentata. — The animals of this order possess no canine teeth, many of them have no incisors, and some of them have no teeth at all, hence the name edentata, or toothless animals. The sloths, ant-eaters, armadilloes, and porcupine ant-eaters of Australia, constitute this order. 8. Pachydermata. — This collection of ^^«cA-«Hmwerf animals includes a number of dissimilar forms, which agree rather in the absence of other characters than in the possession of any common to all. They have mostly bulky forms, and thick skins. This order includes the horse, elephant, rhino- ceros, hippopotamus, tapir, and hog. 9. RuMiNANTiA. — This group is distinguished by the pos- session of cloven hoofs, the absence of the incisor teeth in the upper jaw, and the possession of a stomach constructed spe- ciuUy for ruminating, or " chewing the cud." Oxen, sheep, goats, antelopes, deer, the giraiFe, llama, and camel belong to this order. 10. Oetacea. — This order includes the whales, dolphins, porpoises, which are characterized by their fish-like form, and by the absence of hinder limbs. 11. Marsupiaija. — The animals of the preceding groups have been classified mainly in accordance with the nature of the limbs, and the structure of the teeth. This order includes a series of animals having one character in common, viz., a pouch, in which the young are carried for some time after birth. In other respects they vary so much that some might be classed as flesh-eaters, others as rodents, others as eden- tates, and so on. The kangaroos and oppossums are the best-known members of the order. ANIMALS AND THEIR USES. 123 CHAPTER XXIV. CLASSIFICATION— VERTEBRATA II. As we have already pointed out, Mammals are arranged in great groups in accordance mainly with the varying cha- racters of the teeth and limbs. Birds have no teeth and the fore limbs are always wings ; so that the same characters do not avail us. The forms of the beak, and the legs, and toes, however, serve equally well for a rough classification. At the head of the class we have the 1. Birds of Prky with hooked beaks and claws, including such birds as eagles, falcons, hawks, vultures, and owls. Of those grouped according to the form of the beak we have : — 2. Cloven -JAWED birds, so called because the beaks open with a very wide gape for the purpose of catching insects while the birds are on the wing. Swallows, swifts, martins, and goatsuckers are members of this tribe. 3. Slender-billed birds, including the resplendent hum- ming birds of the New World, and the humble wrens of our own country. 4. Tooth-billed birds, in which the upper beak is notched on both sides near the points. Many of our common birds, such as the nightingale, robin, wagtail, thrush, and black- bird, are members of this tribe. They feed almost entirely on insects and worms, but occasionally vary this diet with berries and tender fruits. 5. Cone- billed birds having short, thick, conical bills, adapted for breaking and cutting seeds. The crows, starlings, finches, larks, and sparrows are familiar ex- amples. Of birds specially characterized by the structure of the feet, we have : — 6. Climbing birds. — Commonly birds have four toes, of 124 NATURAL HISTORY OBJECT LESSONS. which three are directed /ore and of goat-skins, 4,500,000, valued at about £450,000. The sheep-skins were brought in greatest numbers from Australia, South Africa, South America, France, and Turkey ; and the goat-skins from Bengal and South Africa. 3. Fur. — If we examine the hairy coverings of the cat we find two kinds of hair growing, intermingled side by side. One kind is short, soft, silky, curly, downy and barbed length- wise. This is the fur. The other is longer, straight, smooth, 'V* 4\' ANIMALS AND THEIR USES. 133 and comparatively rigid. This is the over-hair. Animals which live in cold countries are abundantly furnished with fur, while those which inhabit warm countries for the most part have short dry hairs. It is in the coldest countries that the most beautiful fur-skins are found. On ^ \' ^^XnT^X^^V^VV the living animal the ' """ * ""'^ over-hair keeps the fur- Fig. 92.— Fur and Over-hair. filaments apart, prevents their tendency to felt, and protects them from injury ; the double coat forming a beautiful provision for securing to the animal immunity from cold and storm. "Pelts," or fur-skins, are used either for felting pur- poses, or Si& fancy skins for articles of clothing or ornament. For the latter purpose the fur and over-hair, or the fur alone, is allowed to remain on the pelt. In most cases the over- hair is " the pride and beauty of the pelt, and makes its chief value with the furrier." In seal-skins for ladies' jackets, &c., the over-hair is usually removed. " The skin, after being washed, cleansed of grease, &c., is laid flat on the stretch, flesh side up ; a flat knife is then passed across the flesh substance, thinning it to a very considerable extent. In doing this the blade severs the roots of the long strong hairs which penetrate the skin deeper than does the soft delicate under-fur. The rough hairs are thus got rid of while the fur retains its hold. A variety of subsidiary manipulations, in which the pelt is softened and preserved, are next gone through. The fur next undergoes a process of dyeing, which produces a deep uniform tint, and causes the filaments to lose their natural curly character. If we look at a lady's seal-skin jacket we at once observe its rich brown colour, and the velvety softness and denseness of the fine 134 NATURAL HISTORY OBJECT LESSON'S. hairs composing it. If this be compared with the coarse, hard, or salted dry seal-skin as imported; or, still better, with the coat of the living fur-seals, one is struck with the vast difference between them, and wonders how the coarse, oily- looking, close-pressed hair on the live animal can ever be transformed into such a rich-looking and costly garment."* For the second purpose, that of felting, the fur is removed from the pelt. After slight preparation by the aid of hot water, the fibres mutually interlace, under pressure, into a compact textile fabric called felt. The best fur for felting is that of the hare, rabbit, and beaver. Some of the fancy furs are of great value, because of their great beauty and scarcity. The value depends on weight, pliability, elegance of texture, delicacy of shade, and fineness of over-hair. A choice specimen of the sea- otter has been sold for £100, and a fine silver fox skin will sometimes fetch £40. The yearly collection of fur- skins alone thoughout the world has been estimated at over 30,000,000, not including those used for felting purposes. The squirrel ranks first, as many as 6,000,000 animals being yearly slaughtered for the sake of their skins. Siberia yields the main supply of skins. Rabbit-skins rank first for felting purposes. They are chiefly used for the manufacture of felt hats, and an im- mense trade is at present carried on throughout Europe in them, the statistics of which may be approximately set down thus : France heads the list with an annual pro- duction of 80,000,000 skins. Next comes England, with a yearly total of from 25,000,000 to 30,000,000. Belgium produces about 15,000,000, almost entirely of domestic breed. In Austria and Hungary about 12,000,000 are collected, but these are chiefly retained for home manufac- ture ; 4,000,000 are turned out in North Germany ; while Eussia, Sweden, and Norway are responsible for but * Cassell's " Natural History." ANIMALS AND THEIR USES. 135 2,000,000. The English trade has developed very greatly of late years, and now amounts to- at least £200,000 annually. The superiority of French rabbit- skins over any other lies not only in quantity, but in quality also. No others can compare with them, and large quantities are exported to both England and Belgium. Of late years the Australian colonies have been sending vast quantities to the market ; indeed, in 1882 the number rose to 14,000,000, of an aggre- gate value of £126,000. Paris is the great centre for the preparation of the skins, and from thence dealers dispatch agents all over Europe. The various processes by which the fur is prepared for the manufacture of felt hats are most interesting, but even a cursory description of them would be too lengthy for us to give here. In yield of skins the hare follows next in number after the rabbit, and then the coypus,* musk-rat, cat, and seal. In the year 1883 upwards of 600,000 undressed seal-skins were imported from various countries, chiefly from British North America, Norway, and the United States. Of other pelts 28,000,000 were received, chiefly from Australia, the United States, and various European countries. 4. Wool. — Wool is softer than the more common hair, and the filaments have a wavy character. Examined under a microscope, they are seen to be covered with scales which overlap each other. These scales are attached only at their bases to the cylindrical hairs, and wherever a bend occurs in the fibre the scales are seen to project. If the filaments be placed in reversed directions, the base of one towards the point of another, and pressed close together and pulled, it is clear that the scales will interlock. On this fact depends everything of importance connected with the woollen and worsted manufacture. In short- fibred, or, as it is called, * A lodent, much resembling a beavei-. It lives on the shores of the rivers and lakes of South America. In the fur-trade the skin is known under the name of " nutria," signifying otter. 136 NATURAL HISTORY OBJECT LESSONS. short-stapled, wool, the fibres are more wavy and the scales are more numerous and distinct. This wool is best suited for the manufacture of " hroad-clotli ," while the long-stapled wool is woven into such worsted fabrics as al- pacas, poplins, &c. The principal process in the preparation of woollen yarn for weaving, con- sists in combing or carding the wool so as to lay the fibres side by side, the bases of some being in con- tiguity with the tips of others. In spinning the thread the special use of the scales is seen, they interlock and prevent the thread from untwisting. If we take any hair which has not the special properties of wool we may twist it as much as we like, but owing to its elasticity and want of the projecting scales, it will not retain its twisted form. It is owing to the presence of these scales that wool, like fur, is a suitable material for felting. About 223,000 tons of imported sheep and lambs' wool are used every year in our woollen manufacture, in addition to the produce of our own country: Of this, about two-thirds is brought from Australia and New Zealand. The next largest supplies come from South Africa, Bombay, and Russia. In addition, about 6,000 tons of goats' hair or wool are imported, chiefly from Turkey and South Africa, and about 600 tons of the wool from the alpaca, vicuna, and llama from South America. 5. Feathers. — The beautiful covering of birds which we call feathers is, like hair and wool and fur, but a develop- Fig. 93.- -Fitres ofWool magnified, showing Scales, ANIMALS AND THEIR USES. 137 ment of the epidermis. Feathers differ in their minute con- struction in particular hirds, as also in colour, size, shape, and arrangement, according to their position on the animal. We may roughly classify them as quill feathers, clothing feathers, and down. The quill feathers are mainly con- cerned in flight ; the covering feathers and the down consti- tute warm coverings to preserve the high temperature of the body. Feathers have the following parts in common : — a. A tube, or barrel, or quill — a hollow cylinder, partly em- (o) Tube. (s) Shaft. Fig. 94.— Parts of Feather. (c) Web. bedded in the sac of the skin. b. The stem, or shaft, a con- tinuation of the quill, composed internally of soft, compact, but elastic pith, having the buoyancy of cork. e. The u-eb. From the shaft on either side spring a number of thin plates, at an angle more or less acute with the stem, arranged with their flat sides towards each other ; and again from these plates, or barbs, spring other minute plates similarly arranged, called barbules. This is the web. The barbules interlock, and so retain the barbs in their proper position. 138 NATURAL HISTORY OBJECT LESSONS. In some feathers the shaft is fine and tapering, and the barbs and barbules are long and loose, forming the light and graceful plumule as seen on the ostrich, emu, and some other birds. For commercial purposes feathers are classified as ornamental, common, and down. Many of the ornamental feathers, such as those of the ostrich, the humming-birds, birds of paradise, &c., are very brilliant and beautiful, and fetch high prices. In the year 1883 considerably more than half a million pounds of ornamental feathers were imported, having a value of upwards of two millions sterling. They were brought chiefly from the Cape (nearly one-half), the East Indies, and France and Holland. The feathers im- ported from France and Holland are the produce of their colonies. Of feathers for beds, pillows, &c., nearly 2,000 tons are imported. The beautiful soft, flufiy, light, and warm material known as " eider-down," is supplied by the eider duck. The principal home of this bird is on the bleak and frozen coasts of Northern Europe, and it has many breeding places on the rocky cliffs of the Outer Hebrides, and other islands off the coast of Scotland. The birds pluck the fine feathers from their breasts to line their nests. The owners of the breeding places abstract a portion of both down and eggs, following which the birds provide a fresh supply. A portion of the down and eggs are again taken a second, and a third time. The third supply of down is usually supplied by the male bird. 6. Haik, Bristles, &c. — Every part of the coverings of the common domestic animals is utilised in some way or other. The hair removed from the skins of cattle is used for mixing with the mortar used on ceilings ; the hair from the manes and tails of horses is used for stufiing chairs and sofas, and for weaving into a kind of rough cloth ; the parts of the hides and skins rejected by the tanner are boiled down to make glue ; the horns of cows and oxen are made into combs and many other articles of utility ; and hog ANIMALS AND THEIR USES- 139 bristles are used in the manufacture of brushes. 1,200 tons of bristles, 3,000 tons of cow and ox hair, 800 tons of horse hair, and 6,000 tons of horns and hoofs were imported from various countries for manufacturing purposes in the year 1883. Attention was directed in the last chapter to the shelly- coverings of the articulata, and to the mantles and shells of the moUusca. Many of the animals still lower in the zoolo- gical scale make for themselves houses of stone, which have been and are still most important agents in the economy of Nature.* CHAPTER XXVII. THE BONY SKELETON AND ITS MODIFICATIONS. The complete skeleton of a vertebrate animal may be con- sidered to consist of an essential part — the vertebral column ; and of various appendages, such as ribs and limbs. The vertebral column is of course always present. Its main office is to protect the brain and spinal cord from injury ; but it likewise serves as attachments for the appen- dages — when present — and as a support to the muscular system. The pieces of the vertebral column vary consider- ably in number and development ; but the appendages, according to the varied and distinct purposes for which they are designed, present an almost endless diversity of form. In some of the vertebrates one or other, or all, of these appendages may be wanting. Without pretending to enter into a consideration of the precise details of the structure of the skeleton, it is necessary for the proper understanding and appreciation of the various • See Lesson XI, VII., Part II. liO NATURAL HISTORY OBJECT LESSONS. and beautiful adaptations of structure to habit, to have a Kg. 95.— Skeleton of Gorilla. general acquaintance with the position and uses of the vari- ANIMALS AND THEIR USES. Ill ous parts. We may take the human skeleton as a basis for comparison. The head consists of the skull, or cranium, and the face. The skull is a bony case formed by the union of eight bones, in which the brain is lodged and protected. In its base there are openings for the nerves which pass from the brain ; and for the admission of blood-vessels which nourish the brain. The face is built up oi fourteen bones, all of which, with the exception of the lower jaw, are united firmly to each other and to the skull. They enclose five cavities for the lodgment and protection of the organs of sense, viz., sight (two cavities), smell (a double cavity), and taste. The vertebral or spinal column consists of thirty-three small bones, called vertebrae.* They are joined to each other by pads of cartilage, which provide for a certain amount of motion, and springiness. Seven of these bones form the neck f vertebrae ; twelve the back,t and five the loin t vertebrae. Below these are five, which, though sepa- rate in the young, are united to form one bone — the sacrum — in the adult, and then four others, also united in the adult to form one bone, the coccyx. The first of the neck verte- brae, called the atlas, is more movable than the rest. The skull rests on this bone in such a manner that the head is free to nod backwards and forwards. The atlas itself turns on a projection from the next bone — the aoois — as on a pivot, permitting the rotatory movement of the head. The dorsal or back vertebrae are those to which the ribs are attached. In man there are twelve pairs of ribs, which curve round and enclose the chest. Seven pairs — the true ribs — are joined by cartilage to the sternum or breast-bone ; three pairs — the false ribs — are joined to each other and to the seventh pair in a similar manner, and the remaining two pairs are free, and are called floating ribs. The two pairs of appendages, called in men arms and legs, are more or less closely connected with the central frame- • From vifrU, to turn. t Cervical, dorsal, lumbar. 142 NATURAL HISTORY OBJECT LESSONS. work by means of other bones and ligaments. The connect- ing link of the arms consists of the flat blade-bone, and the cylindrical co^^ar-bone. The connecting bones of the legs are attached to the sacrum. The bones of the arms and legs are joined to each other and to the connecting links by ball- and-socket and hinge joints ; and they form, with the assis- tance of the muscles attached to them, a series of beautiful natural levers. In number, structure, and position, the bones of the superior and inferior members are somewhat analogous. (See Fig. 95.) It will be impossible to do more than glance at a few of the many variations in the structure of the bony skeleton of vertebrate animals. It is a curious fact that the number of neck vertebrae is the same in all mammals. The long- necked giraffe has only seven, while the elephant and the whale — animals which seem to have no neck at all — have also seven, although of course they are very thin. Birds have a larger number of neck vertebrae, the graceful swan having as many as twenty-three. The tortoises and lizards possess neck vertebrae, but in snakes and fishes they are wanting. Dorsal vertebrae have been defined to be those which carry ribs. Most mammals have more ribs than man. The ele- phant has twenty rib-supporting vertebrae. But it is among the snakes and fishes we must look for an enormous develop- ment in this respect. The python has nearly three hundred pairs of ribs, and in this and other members of the snake tribe, where arms and legs are absent, those ribs become organs of locomotion. They are connected on the one side with the vertebrae by ball-and-socket joints, while the other ends are free, that is, they are not joined to any sternum. They are, however, connected by muscles with the scales on the lower surface of the body, and it is by the action of these muscles on the ribs and scales that the snake is able to crawl. The animal progresses, so to speak, on the ends of its movable ribs, just as a caterpillar walks on its many legs. ANIMALS AND THEIR USES. 143 No members of the fish tribe, and but few of the reptiles, have either lum- bar or sacral ver tebrse, but the bones of the tail become in some groups very nu- merous. Thus the python and the conger-eel each have 102, while the shark has 270. In man and in mammals gene- rally, the verte- brae are joined by pads of carti- lage; but in the snakes and fishes a different plan is adopted. In the snake each vertebra has a rounded projec- tion in front, and a hollow, like a cup, behind, and the "ball" of the one bone fits in- to the " socket " of the other, forming a chain of bones characterized Jjy great flexibility and strength. Fishes are buoyed up and supported by the element in 144 NATURAL HISTORY OBJECT LESSONS. which they live, and require flexibility rather than strength in their bony framework. In this class therefore the yertebrse present cups or sockets on both sides, and the rim of the socket of one bone fits close to the rim of the socket of the next bone. A hollow sphere is thus formed, and this encloses a bag containing a fluid over which the concave surfaces of the vertebrae freely play. A chain of bones is thus formed yielding extreme flexibility, but less strength than the ball-and-socket series of the snakes. The vast majority of the vertebrate animals possess two pairs of limbs, corresponding to the arms and legs of man. They are present in all mammals, except that the hinder pair is wanting in the whale tribe. Birds invariably have both pairs. Of the reptiles, the crocodiles, tortoises, and lizards have both pairs ; snakes have neither ; while frogs and toads, possessing none in their young state, develop both pairs as they take on the adult form. The primary object of the limbs is locomotion, and in no part of animated nature is beauty and simplicity of design more manifest than in the adaptation of the structure of the limbs to the different modes of progression, whether walk- ing, running or leaping on the ground, climbing and swing- ing in the trees, flying in the air, swimming on or beneath the surface of the water, or burrowing and tunnelling in the earth. The variations depend less on the number and arrangement of the bones, than on the special development of one or more to suit special purposes. Monkeys find their home among the leafy branches of great forest trees, and they swing and jump from bough to bough with wonderful alacrity. ISTow a foot, like that of man, would not be a very serviceable member for clasping and climbing ; but by a simple change of position in the bones, particularly in those which in man qpnstitute the skeleton of the great toe, a hand is formed ; inferior, it is true, to the ANIMALS AND THEIR USES. 145 nand of man for performing delicate operations, but possess- ing great power of grasping. Bats capture their insect prey in the air, and they must have wings for flight. By a modification of the size and form of the bones of the fore limbs, a framework for the wings is formed. The metacarpals are greatly lengthened, and to a less extent the phalanges, so that the middle E 146 NAXUEAL HISTOEY OBJECT LESSONS. finger becomes longer than the whole body. The thumb- bones are small, and the thumb ends in a sharp curved claw. The hind limbs are of ordinary size, and are armed with claws. There is another interesting modification in the skeleton of the bat. This we find in the bones of the lower arm. These in man and in most of the lower animals are two in num- ber (see Fig. 95), and they are connected at the elbow and the wrist in such a manner as to per- mit of the rotatory mo- tion by which the palm of the hand may be turned upwards or downwards. But in the bat such a power of motion would be a source of weakness rather than of strength, unless the muscles were made disproportionately powerful, for the pressure of the atmosphere against the wing would turn it sideways at every stroke, and thus cause it to cleave through the air instead of beating against it. One bone, therefore, of the forearm — the ulna — is not developed, or is present only in a very rudimentary form attached to the radius near the elbow, so that a twisting motion of the arm or wing is impossible. The bones of the legs and feet of the cat and dog families ANIMALS AND THEIR USES. 147 and their allies correspond in number and position almost exactly with those of the foot of man ; but the carpal and metacarpal bones are set on the radius and ulna, and the tarsal and metatarsal on the tibia and fibula, in such a way that they practically form a portion of the legs ; they are lifted well above the ground, and the animals walk with an elegant and silent tread on the very tips of their toes. That which looks like the knee of a cat or dog is really the wrist, and that which appears to be a backward-turned knee in the hind leg is really the heel; the true elbow and knee are close to the body and almost hidden by the skin. The only carnivorous animals which walk with the sole of the foot on the ground are the bear, racoon, glutton, and beaver families. In the limbs of the sea-lions and seals all the ordinary bones are present ; but they are developed so as to form a strong internal framework, which, with the cover- ing hard membrane, form efficient paddles for swimming. The arm- bones are short while the finger- bones are long, so that the fore- flippers show little more than broad hands distinct from the body. In the hind limbs the 148 NATURAL HISTORY OBJECT LESSONS. thigh-bone is short, while the leg-bone and the phalanges are long. In the common seal the legs are directed back- wards almost in a line with the body, and are closely bound to the tail by a membrane as far as the heel. In the whale tri'be the fore limbs resemble those of the seals, while the hind limbs are wanting. Most of the rodents have the hind legs longer and more powerful than the fore legs, and the latter, serving as they often do in a certain degree as hands, have the ulna and radius distinct. They usually have five toes, but this number is reduced to four, and even to three, on the hind feet. Our common domestic animals, the horse, ass, cow, sheep, and pig, as also the rhinoceros, hippopotamus, and tapir, walk on one or more toes. The leg of the horse is a beau- tiful adaptation for the purpose of strength, speed, and springiness. The upper and lower arms and leg bones cor- respond with those of most other mam- mals, except that the ulna and the tibia are absent, but the bones corre- sponding to our hands and feet are changed almost out of recognition. The bones of the knee of the fore leg and of the backward-turned knee of the hind leg, correspond to those of the wrist and ankle. If we except two small bones, called splint bones, only one metacarpal and one meta- tarsal bone is present, with three pha- langes at the end of each. The meta- carpal and metatarsal (cannon) bones are elongated and strengthened, and set upright on the first of the phalanges. The last of the phalanges is partly enclosed by a hoof which corresponds tothe finger nail. The rhinoceros and tapir have each three toes ; the hippo- Fig. 100.— Foot of Horse. ANIMALS AND THEIK USES. 149 potamus, the pig, and the ruminants* generally, have four toes. Fashioned on the same principle as that of mammals, the skeleton of birds differs materially in some respects. In the first place the bones of the limbs instead of be- ing solid, or filled with marrow, are hollow; and for these reasons, as sup- ports for the powerful muscles they must be strong, and for the at- tachment of these mus- cles they must be large ; while at the same time they must not be too heavy, or flight would be impossible. In the second place the bones of the fore limbs are modified to suit the re- quirements of a wing instead of a hand or leg. The bones of the fore- arm are lengthened, the increase in length bearing relation to the power of flight, while the hand is reduced to a single piece for the support of the large feathers of the wing. A rudimentary thumb and the vestiges of a third finger are, however, present. In the hind limbs the thigh-bone is short and directed forwards, the leg-bone is longer and composed of but one strong bone, while the ankle and foot-bones are represented by one bone, which practically forms a lower leg-bone. It is the length * In the sheep and ox two are mere rudiments, and in the camel and giraffe two toes only are present. Kg. 101.— Skeleton of Vulture. 150 NATURAL HISTORY OBJECT LESSONS. of this bone which determines the height of the bird when standing. In the tortoises and turtles the skeleton undergoes a pecu- liar modification, to assist in the formation of a great plate, called the carapace, which covers the animal as with an um- brella. This carapace is formed of the vertebral column, Kg. 102.— Skeleton of Turtle. the ribs, and certain bony plates in the skin, all grown toge- ther (see Fig. 102). It may be covered with a leathery skin, or with a horn-like substance called tortoise-shell. The under plate, or plastron, is not formed by the bones of the skeleton, but by dermal or skin bones. The bones of the carapace ANIMALS AND THEIR USES. 15l and plastron are consolidated and motionless ; not so the neck, tail, and limb-bones. The latter are as free as in the typical mammal, and all the chief bones are present. Fig. 103.— Skeleton of Frog. The skeleton of the frog also shows some interesting modifi- cations. The bones which connect the limbs with the vertebral column are large and strong ; and so are the "transverse pro- 152 NATURAL BiSTOEY OBJECT LESS0X8. cesses " of the vertebrae. The latter, in some measure, compensate for the absent ribs. As the fore limbs are less used by the animal than the hind limbs, the bones are shorter and smaller. In the fore limbs the radius and ulna, and in the hind limbs the tibia and fibula, form but one bone. There are sia: wrist and six ankle bones ; but two of the latter are very much elongated, and have all the appear- ance of the usual double leg-bones. In the hind legs the metatarsal bones and phalanges are very long. They support the swimming-web. The pectoral, or breast fins of fishes, represent the fore- limbs of the higher vertebrates; and the ventral, or belly-fins, represent the hind legs. Sometimes one pair, and occasion- ally both, are absent. CHAPTER XXVIII. TEETH— THEIR VARIETIES AND USES. The food of most of the mammals requires to be cut, or crushed, or ground, before swallowing. For this purpose teeth are pro\ided. They are fixed partly in the upper jaw and partly in the lower, on either side, and in front of each. The lower jaw only is movable. The number of teeth, the kind of teeth, and the particular motion of the lower jaw depend on the kind of food on which the owner feeds. Our own teeth may be taken as the best example with which to compare the teeth of the lower animals. They are of three kinds adapted to as many different purposes. First, there are four chisel-shapod teeth in front of each jaw, adapted for cutting like a pair of shears ; these are named incisors, or cuttiiig teeth. On either side of the incisors in both jaws we find one long conical tooth. In many animals, ANIMALS AND THEIK USES. 15S particularly in ttose which live on flesh, these teeth grow much longer than the others, and become very prominent. For instance, they are prominent in the dog ; and it is from their resemblance to these teeth of the dog that ours are called canine, or dog-like teeth. There are of course four canine teeth. They are not adapted for cutting the food, but rather for seizing and tearing asunder. Behind the canines we find teeth of the third kind, having large, irregular, flattened surfaces adapted for grinding the food. These are called molars, or mill-like teeth. When all are present there are ten in either jaw, five on each side. In the adult man or woman therefore, when the teeth are perfect, they number thirty-two — eight incisors, four canines, and twenty molars. Each tooth consists of the root ov fang, the neck, and the crown. The crown is the part seen above the gums. Teeth are made of a hard bony substance named dentine ; but the crown of the tooth is covered with a much harder substance still, called enamel. There is a small space in the centre of each tooth, and the walls of this chamber are covered with a membrane filled with nerves. When through accident or decay the dentine is destroyed, and this nervous mem- brane is exposed to the air, tooth-aclie often follows. We have already stated that the kind of teeth, and the motion of the lower jaw, vary according to the nature of the food. So exact is this correspondence that it is often possible to determine, by the simple inspection of the teeth of an auimal, not only the nature of its food, but also the general structure of its body, and even its ordinary habits. The teeth of the monkey tribe resemble those of man, except that usually the canine teeth are much larger. They are admirably adapted for biting, and tearing, and grinding the vegetable food, hard or soft, on which the animals feed, and fortunately for their owners, they never decay. It is a curious fact that the monkeys of the New World 154 NATUEAL HISTORY OBJECT LESSONS. have four more molar teeth than the monkeys of the Old World. Animals of the cat-family, which feed exclusively on flesh, have the incisors small ; but the canines, which seize and hold their prey, and which penetrate and tear asunder the flesh, are remarkably developed. Flesh food requires cutting and not grinding, hence the molars are compressed so as to form cutting edges which work against each other like the blades of a pair of scissors. The jaw, too, can only work up Fig. 104.— Cat's Teeth. , , . , ■■ i . i and down ; it has no lateral motion like the jaw of the horse to adapt it for grinding. The members of the dog-family are also flesh-eaters, but not exclusively, and so their teeth are modified accordingly. The scissor-like cutting-edges of the two back molars — upper and lower — have disappeared, and the teeth have become real " grinders." In the bear-family the teeth are again still further modified to suit the mixed flesh and vegetable diet. Four molars in each lower jaw and three in each upper, instead of having the sharp cutting character they have in the cat, have comparatively flat crowns, with slight elevations fitted for grinding. There is also a corre- sponding change in the movement of the jaw. It is no longer a hinge movement, but the jaw can be worked from side to side, and the bear can actually grind his food. In the aquatic carnivora — the seal-tribe — the dentition again changes to suit the habits of the animals. The teeth are specially formed for seizing and holding the slippery prey on which they feed ; and for dividing the body of the fish they devour into large pieces. The peculiar scissor-like cutting molars of the land carnivora are replaced by teeth ANIMALS AND THEIE USES. 155 either serrate, or saw-like in character, or somewhat flattened crowns with conical projections. In the walrus, while the lower jaw has neither incisors nor canines, the canines of the upper jaw — tusks, they are termed in this animal — are of great length and strength. They are sometimes as much as two feet in length, and weigh twelve or fifteen pounds. They are used by the animal for the purpose of procuring food. Part of its time is spent on the shore and in shoal water, and the tusks are used for digging up mussels and cockles and Kg. 105.— Teeth of Seal. other shell-fish. They also serve another purpose. When the animal wishes to get from the water on to the ice the tusks are dug into the ice with great force, and the body is hauled up. They are also used as powerful offensive wea- pons. Unlike any other teeth previously mentioned — which, when full-grown, cease to increase in size, these teeth grow continuously as they wear away. The teeth of bats, again, vary in structure according to diet (see Fig. 97). . By far the larger number of these little nocturnal animals feed on insects. These have small but 156 NATURAL HISTORY OBJECT LESSONS. sharp-pointed teeth, adapted for crushing the hard enyelopes of insects. Such teeth are of course unsuitable for mastica- tion, and the jaws of the bat move up and down only, much like the jaws of the cat. The fruit- eating bats have small molar teeth with rounded projections adapted for grinding their food ; while bats which get their food by sucking the blood of other animals have long and lancet-shaped canines for making incisions. The molars, having little or no work to do, are small and imperfectly developeJ. Kg. 106.— Jaws of Hare. The teeth of the insectivora resemble the teeth of the insect-eating bats ; the molars being similarly furnished with sharp points for crushing the hard envelopes of their insect prey. One of the most remarkable examples of the adaptation of the structure of the teeth and the motion of the jaw to the habits of the animal, is seen in the vast group included under the name Rodentia. In these animals, as the name implies, the teeth are specially adapted for gnawing. They are of two kinds only — incisors and molars — and the number ANIMALS AND THEIR USES. 157 of the former never exceeds two* in each jaw. The great incisors are constructed in a manner most efficient for their purpose. In the first place they require to be strong and to be kept constantly sharp, so that the animal may be able to cut through tough and hard vegetables. In the second place provision must be made to make good the loss attribut- able to constant attrition. The teeth are composed of dentine coated along the front surface with a plate of hard enamel. By constant friction the substance of the teeth is worn away, but the softer dentine is worn away more rapidly than the harder enamel, hence the latter is left as a sharp projecting cutting edge. Chisels are constructed on this principle, a thin plate of steel laid along the front of a thicker layer of iron forming the cutting edge. But were no provision made for renewing their substance as fast as they are worn away, the teeth would soon become useless. So these teeth are formed constantly to grow and increase in length. As fast as they wear away above, they are pushed forward from the base. These teeth have no real roots, they are buried far in the jaw-bone, and their buried ends are hollow and filled with pulp, from which new dentine and enamel are being constantly formed. By this means as the teeth are worn away in gnawing, a fresh supply of tooth is being constantly pressed forward to supply its place. As the teeth are constantly growing we see how necessary it is they should be kept in constant use. The gnawiD>g animals have no canines in either jaw, and a considerable space separates the incisors from the molars. The latter vary in number and to some extent in form ; but in most of the rodents the enamel is arranged in transverse plates which, wearing more slowly than the dentine, give to the surface of the teeth a rasp-like appearance; and curiously enough, the teeth are used very much in the same way as a • In hares and rabbits two rudimentary incisors are found in the upper jaw behind the large teeth, but these never render effective service. 158 NATURAL HISTORY OBJECT LESSONS. rasp is used. The lower jaw is so jointed to the upper that it has very little lateral motion ; but, instead, a rasping motion forwards and backwards. This particular motion answers well for the reduction of hard substances, and in addition gives to the incisors a much greater power of gnawing. In all ruminants, except the camel-tribe, incisor teeth are wanting in the upper jaw. The upper canines are more often absent than present, though in a few of the deer- tribe, such as the musk deer, they are enormously developed, pro- jecting far down outside the lip. The molars are well- adapted for grinding ; their surface shows crescent-shaped ridges formed by the projecting bands of enamel. The full complement of teeth in the horse is 40, viz., 12 incisors, 4 canines, and 24 grinders. The canines are small (the upper are not present till old age in the female) and are placed at some distance from the cutting-teeth. A much larger space intervenes between the canines and the grinders. This space is called the har, and receives the " bit." The dentition in the elephant is very interesting and in- structive. As in the rodents, incisors and molars are present. In the Indian elephant, which presents several points of difference from the African elephant, the males alone have well-developed incisors in the upper jaw ; in African ele- phants both sexes are provided with them. These incisors, better known as tusks, grow to a very large size, sometimes reaching the weight of from 150 to 200 lbs., and project a considerable distance from the mouth. Like the incisors of the rodents, they grow from a pulp which is continuallj' forming new tooth material, in this case named ivory. There are incisors in the lower jaw, but no canines in either. Dur- ing the lifetime of the animal it may have as many as 24 molars, but there are never more than two in each jaw at the same time. " These teeth move forward into their working place in the jaw in regular succession, from behind forwards, each being pushed out by its successor as it is gradually ANIMALS ANJD THEIR VSViS. 159 worn away. They present a gradual increase in size as they successiveljr appear. The teeth are worn away not merely by the food on which the animal lives, but also by the parti- cles of sand and grit entangled in the roots of herbs torn up for food, and their wear is compensated by the growth and development of the succeeding teeth. The molar or grind'' ing teeth of the elephant are for the most part buried in the socket, and present little more than a surface for mastication above the gum. Each is composed of a number of trans- verse perpendicular plates, built up of a body of dentine, covered by a layer of enamel, and this again by a layer of cement, which fills the interstices be- tween the plates and binds together the divisions into one solid mass. Each of these ena- mel plates, how- ever, in the perfect tooth, is united at the base. The difference between the grinders of the Indian and African elephants is well marked. In the former, the transverse ridges of enamel are narrower, more undulating, and more numerous than in the African, in which latter species the ridges are less parallel, and enclose lozenge- shaped spaces." The tusks of the wild boar are largely developed canines ; but they grow in a manner precisely similar to the growing teeth of the rodents and the tusks of the elephants. The teeth of the cetaceans vary considerably in the dif- ferent species; but generally they are numerous, simple, sharp, and of a conical shape, suitable only for seizing and retaining their living prey. Two exceptions deserve special Fig. 107.— Teett of Elephant. 160 NATURAL HISTORY OBJECT LESSONS. notice. The first of these is the narwhal, or sea-unicorn. The male narwhal has one canine tooth of the upper jaw, occasionally both, developed into a long spiral tusk, project- ing straight forward, sometimes five or six feet, in front of the head. The narwhal has no proper teeth. The other excep- tion is that of the whalebone whale, whose upper jaws and palate are provided with plates of whalebone instead of teeth. These plates are composed of a horn-like material, similar to that of which our finger-nails are made ; the free edges are split into fibres, and the fixed ends are embedded in the gums of the upper jaw, like the finger-nails are embedded in the flesh of the fingers. The plates grow continuously from the roots, and at first consist of a brush of hair-like bodies ; these gradually lengthen, and at the same time the part near the root becomes the solid horny substance known as the blade. The transverse arrangement of the plates, several hundreds in number, with split and fringed inner and lower edges, causes the mouth, when open, to have the appearance of a great hairy archway. The purpose of this complicated arrangement of fringed plates is that of a sieve. The whale feeds on small creatures, and vast quantities are required to satisfy its hunger. The animal opens its huge mouth and takes in a quantity of water containing its minute marine food, and then, closing it, the water escapes, while the tiny prey is entangled in the hairy meshes. Last amonff the mammals are the edentates or "toothless" o animals — the ant-eaters, sloths, and armadilloes. These have neither incisors nor canines, and some have no molars ; but most of them have a few of the latter kind, simple and conical in shape, but without the usual covering of enamel. Their food consists of soft-bodied insects, and, in the case of the sloth, of soft leaves and twigs, hence teeth are little needed. Birds have no teeth. Reptiles and fish have many teeth ; but generally they are of a much less complicated nature ANIMALS AND THEIR USES. 161 than those of mammals, being simply conical and curved backwards for the purpose of preventing the escape of prey, rather than for cutting or grinding. But innumerable modifications occur. Thus the teeth of the deadly shark are flat and lancet-like, the cutting edges being notched like a saw; the front teeth of the flounder are flat grind- ing teeth ; other fish have convex teeth, so numerous and so closely packed over a broad surface, as to resemble rig. 108.— Skull of the Cape Ant-eater. the paving-stones of a street ; a few have teeth which resemble bristles, and these are set together like the hairs of a brush. The common perch has teeth still more slender, being so minute and numerous as to resemble the pile of velvet. The well-known pike is armed with teeth scarcely less formidable than the canines of a carnivorous mammal, while the sturgeon and a few other fish are entirely toothless. CHAPTER XXIX. TONGUES, The Tongue is the special organ of taste ; but the " unruly member " has other and no less important duties assigned to it. In man it is one of the chief instruments of speech. In L 162 NATURAL HISTORY OBJECT LESSONS. mammals, generally, it is the chief guide in the choice of food, and an important assistant in the act of mastication and in the process of deglutition. In a few of the mammals, and in some of the birds and reptiles, it is modified into an efficient organ of prehension. The structure of the tongue diflfers but little in the mammalia. It is a fleshy organ covered with a mucous membrane or sliin, and fastened at one end to the floor of the mouth. The mucous membrane is covered with little pro- jections, called pa2)illce. Some of these papillae are concerned with taste,others with more mechanical work. In the cat-tribe the latter are horny and pointed backwards. They serve as rasps to scrape off the smaller frag- 1\^9®' ments of flesh from the bones. So Fiff. 109.— Oat's Tongue. , , , j.i_ • it, v large and sharp are they m the iion, that a stroke or two of the tongue would take the skin from a man's hand. Cats and dogs, and their relations, use the tongue for lapping liquids. 'Animals which " chew the cud " have long tongues which aid in taking food into the mouth. In the case of cut grass, or hay, the tongue is the only organ used in gathering food. In cropping grass, or other growing herbage, the food is drawn into the mouth by the tongue and pressed by the lower incisors against the hard pad of the upper jaw, and then torn off with a jerk of the head. In the giraffe the tongue can be lengthened or shortened in a very curious way. This animal feeds on the leaves of trees which are gathered by the tongue, and this organ is so delicate that it can grasp and pluck a single leaf selected at will. Other mammals have their tongues not only lengthened, but covered near the free end with a gummy substance, or even with hairs, to collect food. Thus, in some of the bats the long pencil -like tongue is set with recurved bristles, a«id ANIMALS AND THEIE USES. Ib3 can be protruded to a considerable distance. These bats feed on soft fruits, and no doubt when the tongue is pressed into the soft pulp and with- drawn, the bristles retain a large quantity of the food. In the ant-eaters the long projectible tongue is covered with slimy sa- liva. Their favourite food A^' T^ is ants, and these they _. ,,„ ^ ,.„.,,, „ ', ,. ^■^ Fig. 110.— TonguBot Fruit-bat. collect by pushing the tongue into holes they make with their claws in ant-hills. The tongue having made its entry is soon covered with the insects, which are held fast by the saliva, and carried into the mouth as the tongue is withdrawn. The great ant-bear opens the ant-hills with his powerful claws, and then as the insects flock from all quarters to defend their dwelling, draws over them his long flexible tongue covered with glutinous saliva to which they conse- quently adhere. So quickly is the operation performed that it is said the animal can take two helpings of food in a second. In many birds the tongue is covered with a horny sub- stance, so that it can be of little use as an organ of taste. In other birds it is but slightly developed, and in the pelicans it is entirely wanting. In birds of prey it is broad and soft. In parrots the tongue is fleshy, and is used for holding solid substances against the upper beak, while the lower gives it another bite. The most unique tongue in the class of birds is that of the woodpecker. In this bird it is developed into a long thin organ adapted for the collection of insects from deep holes and crevices. It tapers to a slender horny point, the sides and upper surface of which are beset with bristles pointing backwards and moistened with a thick glutinous saliva. This bird can project and withdraw this tongue with marvellous rapidity. 164 NATURAL HISTORY OBJECT LESSONS, In some of the larger reptiles the tongue is fleshy and covered with a thick rugged membrane sometimes beset with Pig. 111.— Tongue of the Woodpecker. pointed papillae ; but in general it is thin, dry, very pro- tractile, and cleft towards the end. In two or three species of reptiles, however, the tongue is deve- loped into a remark- able instrument for the capture of prey. In the curious cha- meleon it is worm- shaped, and can be thrust out to a length of several inches with singular rapidity and certainty. The tip iS thickened and slightly Fig. 112. — Tongue of Chameleon. ANIMALS AND THEIR USES. 165 cup-shaped, and covered with a sticky secretion. The chameleon is very slow and measured in its general move- ments, but the tongue is very active. The animal does not chase its insect prey ; but watches and waits until the insect comes within reach, when at first it slowly protrudes its tongue as if taking aim, and then darts it forward with lightning-like rapidity and unerring precision. The prey is held fast by the glutinous secretion and carried into the mouth. In the frog, again, the tongue plays the leading part in the capture of prey. The soft and fleshy tongue of this animal, and its ally the toad, is fixed on the front in- stead of on the back of the floor of the mouth. When in repose the free end is at the back of the mouth, but when the animal ~ ongue o log. puts it out the tip reaches to a considerable distance outside the mouth. " When the frog sees an insect which he desires to catch, he approaches within striking distance, and then flips his tongue at the victim. As the tip is always anointed with a glutinous matter, something like treacle in consist- ence, the insect adheres to it and so is flung down the throat." The action of the tongue is so rapid that the eye can hardly follow it ; something pink flashes from the frog's mouth, and the insect has vanished. Some of the invertebrate animals have wonderfully- con- structed tongues. In the limpet, periwinkle, slug, and whelk, the tongue is a ribbon covered with rows of micro- scopic teeth forming a most efficient ribbon-saw. They are used for scraping, in the same way as a cat uses her tongue ; or for boring through hard shells, and then "licking" out the contents. 166 NATURAL HISTORY OBJECT LESSONS, CHAPTER XXX. TAILS AND THEIR USES. Tailless animals among the vertebrates are the exception. The man-like apes and a few of the rodents among mam- mals, and frogs and toads among reptiles, have no tail ; but the vast majority can boast of a caudal* appendage. It may be but a mere rudiment, seemingly of little use to its owner ; or it may form one of the most interesting and important organs of the body. It is useful as well as orna- mental ; its duties are numerous and varied. It may be an index of the feelings, an engine for locomotion, a rudder to guide, a weapon of offence, a covering for warmth, and even an umbrella to protect from the inclement weather. Many of the monkeys of the new world — the howlers and spider monkeys — are provided with prehensile tails, by means of which they clasp and hang from the branches of trees, while their hands are at liberty for other purposes. These tails must of course be very muscular and strong ; but, in addition, the under surface near the tip — a part destitute of hair — is endowed with an exquisitely sensi- tive sense of touch. These animals can therefore with their tails feel here and there for anything to catch hold of with- out looking, as they make their way from branch to branch. As we have already seen, the bony framework of the tail is but a continuation of the vertebral column, but to yield the necessary flexibility the vertebrae are very numerous. These tail-bones exhibit a striking example of the adaptation of structure to habit. To sustain the weight of the animal the tail must embrace the support very closely, and the nerves and blood-vessels would be liable to severe pressure ; to prevent this there are two curious projections from the lower * Cauda, a tail. ANIMALS AND THEIK USES. 167 part of the body of each vertebra (shaped together like the letter V), between which these organs pass without being pressed upon. So perfect is this tail, and so wonderful in its movements, that it has with good reason been called a fifth hand. It clasps so firmly that, when shot dead, the animal has been known to hang for several hours by its tail before falling to the ground. Fig. 114. — Prehensile Tiiils. Opossum and Young. A few other animals besides the monkeys have prehensile tails. The smallest of them is the active little harvest mouse. With the aid of its long slender tail this animal climbs up the stalks of corn, and other grasses, as nimbly as a monkey climbs among the branches of trees. In descending it twists its tail round the stalk, and slides grace- fully to the ground. The opossums, and some of their 168 NATURAL HISTORY OBJECT LESSONS. relations, many of whicL. are natives of America, and others of Australia, are also gifted with prehensile tails. In some of the American species the tail is put to a very curious use. The young are carried on the back of their mother, and with their tails they cling on to her tail, which is curved over her back for the purpose. Many tails again are bushy, and covered with warm hair and fur. The fortunate possessors of such tails, as they lie down, curl them round to the front and cover their fore-paws and noses for the sake of warmth. The squirrels, the fox, the dormouse, the lemurs, and many other animals make use of their tails in this way. The long bushy tail of the so-called flying-squirrel serves as a sort of rudder to guide the animal as it glides through the air in its long jumps. The feathery tails of birds serve a similar purpose. The tails of some animals serve to give expression to their feelings. When a dog approaches another dog, or a man in a hostile frame of mind, its tail is held erect and quite rigid, but when in a friendly spirit it is lowered and wagged from side to side. Fear is shown by a further depression of the tail, and the dog slouches away with " its tail between its legs." The cat, in anger, lashes her tail from side to side; but when she runs to meet her mistress, or to take her food, her tail is held quite stifi" and perpendicularly upwards. The cow and the horse have but a scant covering of hair on their skins, and they are consequently liable to attack from insects which pierce the skin and suck the blood, so nature provides these animals with long tails which act as " fly-flippers." "The great ant-bear makes neither nest nor burrow, its ample tail serving as its sole protection against the incle- mency of the weather." " He is slothful and solitary, and the greater part of his life is spent in sleeping. When about to sleep he lies on one side, conceals his long snout in the fur of his breast, locks the fore and hind claws into one ANIMALS AND THEIK USES. 169 another so as to cover the head and belly, and turns his long bushy tail over the body, covering the whole as with an umbrella." 'Fig. 115. — Kangaroo Eat. The kangaroo uses its tail as a fifth leg. When resting and feeding it supports itself on its hind legs and its tail. The jerboa-kangaroo has a prehensile tail, and makes use of it in collecting grasses with which it constructs its nest. " As may be easily' imagined the appearance of this kangaroo 170 NATURAL HISTORY OBJECT LESSONS. when leaping towards its nest, with its tail loaded with grasses, is exceedingly grotesque and amusing." All the vertebrate animals which spend the whole of their lives in the water, as well as some others which spend a portion of their time on land, use their tails as sculls and rudders ; sculls for propelling the body forward, just as a boatman propels his boat by a single oar worked from the stern of his boat ; and rudders to turn the body so that it may move in any required direction. On land the crocodile uses its tail as a weapon of destruction. It stupifies its victim with a blow from its tail, and then drags it into the river, where it is soon drowned. CHAPTER XXXI. THE POSITIONS AND FUNCTIONS OF THE PRINCIPAL INTERNAL ORGANS OF ANIVIALS. Wo have now to consider the positions and functions of the principal internal organs of animals. Taking the human form as the model for comparison, we may refer to the brain, the heart, the lungs, the stomach and intestines, and the liver as the chief organs. The brain is contained in a box of hard bone called the skull, or cranium. The heart and the lungs are the chief organs of the chest or thorax,' while the organs concerned in the digestion of food are enclosed in the lower half of the trunk called the abdomen. The thorax is separated from the abdomen by a convex muscular sheet, the diaphragm. The Nervous System consists of the bt-ain and spinal cord, and the nerves connected therewith which traverse every part of the body. The brain consists of a mass of soft substance, a white internal portion and an exterior layer of grey matter. The latter is arranged in folds in such a way that it looks like a handkerchief crumpled up. The spinal cord is con- ANIMALS AND THEIR USES. 171 tained in the canal of the vertebral column. It passes through an opening in the base of the skull, and is thus con- nected with the brain. Like the brain it consists of white and grey matter, but here the grey matter forms the internal portion. The nerves are small white cords which carry messages to and from the brain. "We have special organs of sight, smell, taste, and hearing, and a general sense of touch in the skin, and one set of nerves carries messages to the brain from these organs. A second set of nerves carries messages from the brain to set the muscles in action. In addition to the nervous system of the brain and the spinal cord there is another nervous system consisting of small masses of nerve matter, called ganglia, lying prin- cipally at the sides and in front of the spinal column. The ganglia are connected with each other and with the spinal cord by con- necting nerves, and they send off nerves which form great networks upon the heart and about the digestive organs. Respiration. — The speciul purpose of the lungs is to bring the blood into close contact with the air, so that an interchange may take place. The lungs consist of a number of tubes dividing and subdividing from the main tube — the " windpipe " — until finally each little tube ends in a sac or pouch. These tiny sacs are covered with a membrane full of blood-vessels ; and it is in these sacs that the aeration of the blood takes place. Oxygen from the air is taken in through the thin walls of the blood-vessels, and carbonic acid gas and vapour of water are given off. The carbonic acid gas and the water- vapour are the products of the oxida- tion or combustion of our "fuel-food" and the "waste- Fig. 116.— Brain and Spinal Cord. 172 NATURAL HISTORY OBJECT LESSONS. tissues." This oxidation produces and sustains the natural heat of the body. A considerable quantity of air is neces- sary to maintain a high body temperature. Circulation. — The heart is the organ of circulation — that is, it is the motive power which carries the blood round and round in the body ; the tubes which carry the blood from the heart are named arteries, those which take the blood to the heart are called veins. Between the small arteries and the small veins, and connecting them, are the minute hair-like tubes — the capillaries. These capillaries Fig. 117- — Wind-Pipe and Air-Tubes -i • ii_ i_ j -one side covered by Lung. go everywhere in the body, through and through the muscles, over and within the brain and spinal cord, through tiiiy holes in the bones to their marrow, to the root of every tooth, and to the base of every hair. The skin is a network of capillaries ; it is impossible to insert the point of a needle anywhere without penetrating some of them So the blood flows everywhere, and in its ceaseless flow it serves a twofold purpose. The fluid portion feeds the tissues and repairs the waste, while the tiny red corpuscles carry the oxygen from the lungs to all parts of the body, and return laden with carbonic acid to be expelled through the lungs. The heart itself is double, and each half contains two chambers, an auricle above and a ventricle below ; and between these chambers valves are placed to prevent the blood from flowing back. The ventricles have thick, fleshy walls. The blood is received by the auricles, and passes into the ven- ANIMALS AND THEIR USES, 173 tricles, whence it is sent out. The right auricle receives the dark red blood from the veins, and the right ventricle sends it to the lungs. The left auricle receives the purified blood from the lungs, and the left ventricle sends it on its way through the arteries and the capillaries, and thence through the veins to the right auricle again. Digestion. — Digestion is the process whereby the nutritive portion of our food is made soluble, and is actually dissolved. The process is commenced in the mouth, but the stomach and the small intestines, the liver, and the pancreas or sweetbread are the chief organs of digestion. In the mouth the food is chewed and mixed with saliva, which partially changes the starchy foods into soluble sugar. In the stomach the food is rolled about, and mixed with another juice, the gastric, which exudes from the walls of the stomach itself. The partially digested food now enters the small intestine, where it gets mixed with the intestinal juice, with the bile from the liver, and with another juice from the pancreas, and these complete the digestive process. The digested food is taken up by little hair-like projections on the inner coat of the intestines, called villi. These villi are full of little tubes — the lacteals — which carry the milky- looking food through a number of glands, and then unite to form one common duct, which passes upwards through the chest and opens into a vein in the neck. The liver, a large Fig. 118.— Diagram of the Circulation. 174 NATURAL HISTORY OBJECT LESSONS. dark brown mass, lying chiefly on the right side of the abdomen, secretes the bile, but it also serves another im- portant purpose — it is the store-house of the "fael-food." The internal organs of all vertebrate animals are con- structed pretty much on the same plan as in man, and they serve similar purposes. As might be expected, however, from his superior intelligence, the brain of man is much larger in proportion to his size than that of any other animal. BE Diapbragmi] E Liver Kg. 119.— Thorax and Abdomen laid open. The most remarkable variation in birds lies in the organ of re>spiration. In mammals the respiration is confined to the lungs ; birds breathe not only through their lungs, but the air penetrates to every part of the interior of their bodies, even into the cavities of the bones. The lungs are fixed to the back of the thorax, and are comparatively small ; their smaller size, however, is more than compen- sated for by the air-sacs which occupy the greater part of the cavity of the chest. JXl'HA.JXLJ^.JUO JXrt±J iXXXiAJX USES. 170 The brains of reptiles are much smaller in oomparison with their size than those of mammals and birds, and the surface in all is quite smooth. The spinal cord and the nerve cords, on the other hand, are more fully developed. The lungs also are much less eflBcient organs for aerating the blood than in the preceding classes ; the respiration is consequently less active and the blood comparatively cold. In most reptiles the heart has three chambers only, viz. one ventricle and two auricles. The single ventricle receives the purified blood from the lungs through one auricle, and the venous blood from ]?;„. 120 the body through the other. A portion of this —Brain mixture is passed on to the lungs and the other ^ ^' part is sent out through the arteries and capillaries, to be returned again by the veins to the right auricle. Fishes live entirely in the water, and get the oxygen necessary for life from the air dissolved in the water, and not directly from the air itself. Lungs would be unsuitable for this purpose, and gills are therefore provided in place of lungs. These gills are fleshy, leaf-like organs, filled with blood-vessels, and placed on either side of the head. The water is always washing over and among the fringes of the gills, and the oxygen passes in through the thin walls of the blood-vessels, and the carbonic acid gas escapes into the water. Of course but a small amount of oxj'gen can be got in this way ; the respiration is thus slow and the blood is cold. The heart has but two chambers. The blood is received in the auricle, whence it is passed into the ventricle, and thence pumped through the vessels of the gills to all parts of the body. The brain of fishes is small, quite smooth, and much less compact than in higher animals. The internal organs of Vertebrates are formed on a common plan, modified when necessary to suit the needs of the owner. The same cannot be said of the Invertebrates, 176 NATUEAL HISTORY OBJECT LESSONS. Fig. 121.- -Ganglia and Nerves Df an Insect. although there is a considerable similarity in the organs of some of them. The first forms of animal life possess no special organs of any kind, the body consisting merely of a speck of a thin, jelly-like substance (see Lesson LXV., Part II.). All other forms have a sto- mach ; it may be a simple blind sac, or a straight tube, or a distinct stomach with intestines, as in Verte- brates ; but in some form ^or other it is always pre- sent. In connection with the digestive system, some of the more sluggish forms — such as the oyster, snail, and crab — have large and well- developed livers, while in the more active insects and spiders the liver is so small as to be hardly distinguish- able. There is no brain proper, but in all except the very lowest tribes there are nerve masses connected by, and sending off, nerve cords. In the higher groups the nerve masses become larger and less in number. The blood is colourless, and the heart is wanting; but a circulation is carried on in tubes. Here again, in the higher forms, a swelling in one of the vessels forms a chamber, which may be considered as the simplest form of a heart. The respira- tion is for the most part carried on by means of gills of various shapes and forms ; but the more active denizens of the air and earth — the insect and spider tribes for example — have breathing organs in the shape of air-tubes or air-sacs. PART II. SPECIMEN LESSONS. M NATUEAL HISTOET OBJECT LESSONS, gl iWanual for 'SDtacjbets. SPECIMEN LESSONS. The lessons whicli follow are specimen lessons. All arrangement of systematic courses for the various classes is left to the teacher. "With the exception of three lessons on starch [pages 192- 196], placed together to show how the same subject may be differently treated according to the ages and abilities of the scholars, the lessons are roughly arranged in order of difficulty ; at the same time care has been given to the order of subject. The earlier lessons are suitable for infants' schools, the intermediate for the junior scholars, and the later for the senior scholars of boys' and girls' schools. Less space is devoted to method in these lessons than in those of the former volumes, and less was needed. In most cases the arrangement is sufficient to suggest the method. Unless the teacher is very quick and skilful with the chalk and pencil, the outline figures should be drawn on paper, or on the blackboard beforehand. ISO NATURAL HISTORY OBJECT LESSONS. LESSON I. PAWS AND CLAWS (outline). Oat, or dog, or both, or pictures, for illustration. What are 2Mics ? What are claws p Why so named ? I. The Cat's Paw. Call attention to — Its soft covering oi fur ; the soft pad& underneath, their wse, and why they don't wear out ; the ioe& with the claws; the claws, their number, _^w on each fore- paw, four on each hind paw ; their shape, how their sharp points are preserved, and why. Feel the claws, they are loose, they can be drawn back and hidden ; the cat can put them out when she pleases. [The teacher may very well illustrate the action of the tendons with a fowl's foot. See Lesson LV.] II. The Dog's Paw. Call attention to — Covering of Amr ; the soit pads like the cat's ; claws blunt, cannot be withdrawn. Why the dog does not require sharp claws — catches prey with teeth. Why the claws do not wear away. Compare tcith cat's claws. LESSON II. COCOA-NUT (outline). Foe niustratioii a nut in the husk, sawn through the middle and the halves tied together. A nut without the husk. Picture of cocoa-nut tree. I. The Nut as a whole. Examine the nut in the husk. Three flat sides, surface smooth, brown in colour, hard to the touch. SPECIMEN LESSONS. 181 Show the section, and call attention to the fibre of the outside covering, the hard shell, and the white kernel. II. The Husk. Husk can be separated into string-like pieces — fibres. Distribute some of these among the children and allow them to test: tough and strong. Tell them for what the fibres are used, and show some of the manufactured articles, such as matting, brushes, &c. III. The SheU. Remove the husk and the kernel from one half. Show the shell ; it is very hard ; try to break it ; rough outside, smooth inside, brown colour. The basin-like shape of the half will suggest to what uses the shells may be put. IV. The Kernel. White colour, but brown on the outside. Distribute small pieces. Sweet to the taste, feels oily ; an article of food in the country where it grows. Brought to this country in dried state, and the oil is taken out for the manufacture of candles. V. The Milk. Take the whole nut — shake it, some liquid inside. Show the " eyes ; " open two and pour out the milk. Let the children look at, and taste, for its properties. Show picture of cocoa-nut palm. LESSON III. COTTON AND WOOL (outline). I. The Raw Material. Distribute bits of " cotton-wool " and wool, and small strips of calico and woollen cloth. 182 NATURAL HISTORY OBJECT LESSONS. Gruide the children to examine the cotton and the wool separately, and tell all they can about each. II. Comparison of. Next they should compare the chief properties of the two. Thus both are — (1.) Of a white colour. (2.) Made up of fine threads. (3.) Soft to the touch. (4.) Warm to the touch. (5.) Light. (6.) Tough. (7.) Bend easily. Twist a little of each into a coarse thread to show how strong, and tough, and pliant these substances are. Test each with the flame of a candle. " Cotton-wool " burns easily ; wool frizzles up. III. Manufactured Goods. Now examine calico and woollen- cloth, and compare in the same way. Note especially that the woollen-cloth is warmer and softer than the calico. Show also that both are made of threads which cross each other in and out. Note. — Anotlier lesson of the same kind may be given introducing raw and manufactured silk. LESSON IV. AN EGG (outline). Fob illustration two egge, one of them hard-boiled. I. Shell. — White colour, hard, breaks easily, smooth, thin, egg-shaped. SPECIMEN LESSONS. 183 II. Skin. — Very thin, soft, smooth, elastic. Ill- The " White." — Thick liquid, sticky, can see through it, almost colourless : when boiled — white, elastic, solid. IV. Yolk.— Thick liquid, yellow : when boiled — yellow, solid. LESSON V. ACORN AND HAZEL-NUT (outline). Sttetioibnt specimens of each in their capsules for each child to have one. I. Parts. A nut, and a cup in which it rests. Children may take nut out of cup. II. The Cups. Why so called ? Compare as to shape, colour, and sub- stance. Both smooth inside, but rough on the outside. The cup of the hazel-nut formed of small leaves joined together at the bottom. The edge of the acorn-cup forms a circle. Ill The Nuts. Compare as to shape. Both longer than broad, and both are blunt-pointed at one end, and rounded at the other. The hazel-nut (or filbert) is a little flattened, but the acorn is round like a slate-pencil. IV. The Shells. Alike in colour ; brown when ripe. Shell of hazel-nut thicker and harder than that of the acorn. V. The Kernels. Both white and solid, and covered with a thin brown skin. They differ in taste. That of the hazel is sweet, that of the acorn a little bitter. 184 NATURAL HISTORY OBJECT LESSONS. LESSON VI. MILK (outline). Foe illustration a glass of milk, and a glass of water. I. Properties. — Liquid, white colour, can't see through it, sweet to taste. When " set " cream rises to top. Why P (Illustrate with cork in water.) Compare with water as to colour, taste, transparency, &c. II, Uses — For food, for making butter and cheese. Illustrate the formation of butter from cream by shaking a little warm cream in a warm soda-water bottle. And the formation of curds for cheese by adding a little vinegar to a glass of milk. Filter through cloth. LESSON VIL ONION, TURNIP, CARROT (a comparison). Raw and cooked specimens for illustration. I. Onion. — Call attention to the shape, the thin brown skin, the strong odour, and the hot, burning taste. Cut open to show the leaf-like layers ; show thread-like roots. Compare with a cabbage, or with a lily-bulb. II. Turnip. — In shape something like the onion ; thick skin. Cut open to show solid flesh. Skin has hot taste, flesh sweetish. SMClMEN LESSONS. 185 III. Carrot. — Elongated shape, thin skin. Cut open to show the yellow and red parts. Sweet taste. Turnips and carrots are roots. Show the little rootlets. IV. Comparison. The children to be led to make this for themselves. Onion. Turnip. Carrot. Ball-shape (?) Ball-shape (?) Long. Thin skin. Thick skin. Thin skin. Layers. Solid. Solid. Roots like threads. A tap root. A tap root. Hot, burning taste. Sweetish taste. Sweet taste, Strong odour. Odourless. Odourless. LESSON VIII. CAT AND DOG (a comparison «). IiiUSTEATE by diagrams and pictures ; but if possible with the animals themselves. Cat. 1. Head, roundish. 2. Skin, very loose. 3. Covering, fur.f 4. Paws, with pads and claws. 5. Claws, curved, pointed; can be drawn back. Dog. 1. Jeac?, elongated (usu- ally). 2. Skin, \eTY loose. 3. Covering, hair.t 4. Paws, with pads and claws. 5. Claws, curved or nearly straight, blunt ; cannot be drawn back. • Omit Buch facts as four legs, two ears, and a tail- t Explain the difference 186 NATURAL HISTORY OBJECT LESSONS. Cat. 6. Eyes, large; shielded by curtain in day-time.* 7. Tongue, rough f and dry. 8. Teeth, with sharp points; motion of jaw, up and dovm only. 9. Whiskers, for feeling in dark. Dog. 6. Eyes, large, but not shielded by curtain. 7. Tongue, smooth and wet. 8. Teeth, with sharp points ; motion of jaw, up and down only. 9. Whiskers, for feeling in dark. LESSON IX. DOWN. The teacher should provide specimens of "body feathers,'' especially the finer kinds ; also " eider-down," and if possible a dead bird. I. Introduction, By means of a dead bird — a duck for preference — or by specimens of feathers, show that birds have two kinds of feathers. (1.) Quill feathers on the wings and tail. In most birds these are specially employed for locomotion. (2.) Body feathers intended as a protection from cold. Show, also, how beautifully the feathers are arranged on the body, each overlapping the next and set in regular order, the whole forming a firm, warm coat. The body feathers vary in weight, in size, and in fineness on different birds, and even on different parts of the same bird. The finest and lightest from the breast we call doum. * Explain why. t Explain for what purpose. SPECIMEN LESSONS. 187 II. Properties of Down. Distribute the specimens ; call attention to the fact that down consists of small fluffy feathers, and assist the children by questions to discover those special properties of down for which it is highly prized, such as its lightness, softness, warmth, and elasticity. III. Whence 0]}tained, and Uses. Refer to the immense quantity of geese, ducks, and fowls used as food in this country. Good down for stuffing beds, pillows, cushions, &c., is obtained from these birds, and of course in large quantity. Besides this, we purchase yearly from other countries about two thousand tons of the same kind. The best down is that obtained from a kind of wild duck, called the eider-duck, which frequents the rocky coasts of cold countries in the North. The down is called eider- down. The eider-duck builds a simple nest of twigs, sea-weed, blades of grass, straw, or any similar material it can pick up ; but it lines it with beautiful soft down plucked from its own breast. It is this down collected from the nests which is the lightest and warmest, and therefore the most valuable for making bed coverings and pillows. In some places the birds are looked after and tended as if they were poultry in a farm-yard, and during the breeding season they become quite tame. The farmer provides old boxes, boards covered with brushwood, and other snug corners in which the birds can build their nests, but in return he takes a portion of the eggs and down. The birds then provide fresh supplies, and the farmer again takes his share. When the process has been repeated for the third time, the male bird provides the down. 188 NATURAL HISTORY OBJECT LESSONS. LESSON X. A QUILL-FEATHER. Provide at least one quill-feather for each child. They may be obtained from the poulterer, or from the nearest farm-yard. I. Parts. Call attention to and name the parts : Quill, shaft, iceb. Compare the parts. II. The anill. Covered with thin skin inside and out. Remove this. Quill, a tube with walls which are strong, light, and elastic. Test for these properties : can be cut with a knife, but is softened in warm water and then can be cut more easily. Quill pen. III. The Shaft. Four sides. Filled with white substance — pith. Take out the pith and show that it is tough, light, and elastic. Walls of shaft, tough and strong. Children may try to break it. IV. The Web. Show long, flat pieces placed side by side, fixed firmly to shaft. Draw the fingers down the feather, the "leaves " are ruffled and separated. Draw fingers in opposite direction, leaves take their proper places, and the web becomes smooth again. [If the children are sufficiently advanced to understand, show how the " laminae " or leaves are lightly held together, and how they unite again after being separated. The " laminae" are provided with a vast number of hooks made of thin fibres which project from the edges. Every hook is bent in a certain way. Those on one edge are long, flexible, SPECIMEN LESSONS. 189 and bent downwards, while those which proceed from the opposite edge are shorter and firmer and turn upwards. When two leaves are pressed together so that the long fibres are forced far enough over the short ones their crooked parts fall over the angles formed by the crooked parts of the others, just as the latch of a door falls into the cavity of the catch fixed to the door post.] LESSON XI. GUTTA-PERCHA (outline). For illustration a number of small pieces cut from a sheet; any manufactured articles. I. Properties. Distribute half the pieces among the children and put the other half in warm water. They will at once recognise that it looks like leather ; they will feel that it is tough, flexible, and strong. By experiment it must be shown that it can be cut with a knife, and that it burns with a white flame, giving ofE much smoke, and a peculiar smell. Distribute the pieces from the water. It is now softer ; it can be worked with the fingers and the shape changed. It IB plastic ; it can be moulded into any shape. The children may mould it for themselves. As it cools it gets hard again. Of what advantage is this property in making articles from it ? Illustrate by making a small cup with thin walls. From this show another important property by putting water in the cup. The cup holds the water. Gutta-percha is water-proof. II. Uses. The uses of course follow from its properties. 190 NATURAL HISTORY OBJECT LESSONS. Used for soles of boots and shoes. Why ? Because flexible, strong, and ■waterproof. Why must we not put the soles near the fire ? For bottles, inkstands, frames, whistles, walking- sticks, tubes for gas and water. All these articles are easily made when the percha is soft, and they become hard on cool- ing. Why must we not put hot water in vessels made of gutta-percha ? LESSON XII. LEAVES. Lessons on leaves may take one of three forms — the external form and appearance ; the minute internal structure ; the leaf in action. The idea of this lesson is to direct attention to the size, shape, colour, margin, surface, and veins of any common leaves which the teacher can place in the hands of children for examination and comparison. We will assume that we have for example the leaves of rhuharb, cabbage, scarlet-runner, and strawberry. I. The Rhubarb Leaf. Call attention to the footstalk and the blade. The footstalk is long, large, and fleshy ; flat on one side, rounded on the other, reddish in colour and very juicy, the juice being sour to the taste. The hlade is broad, and it has large veins which run from the footstalk like fingers from the hand ; the colour of the upper surface is a darker green than that of the lower surface. The stalk and veins are smooth and covered with a fine thin skin easily removable when the leaf is young. The margin of the blade is not notched. II. Cabbage. Examine the cabbage leaf in a similar way, and compare with that of the rhubarb. For instance, the footstalk is short, strong, and fleshy, and runs as a great rib to the point SPECIMEJN IiEHSONS. 191 of the blade, while smaller ribs run from it to the edges, and so on. III. Scarlet Bnimer. Note that the leaf is in three pieces and that each piece has a footstalk joined to the larger footstalk of the whole leaf. Examine these footstalks ; they are thin, weak, and grooved. Look at the blade, note its shape and the run of the ribs. Feel the surface of the cabbage leaf and then the scarlet- runner ; the former is smooth, the latter rough. "Why ? The leaves of the scarlet-runner are covered with short, stiff hairs. Compare the colour of the upper and lower surfaces. IV. Strawberry. Long footstalk. Leaf in three pieces each on a short footstalk. Footstalks firm, tough, and covered with hair, grooved in front, rounded behind. Note the shape of the leaf; margins cut like a saw. Compare with margin of scarlet -runner leaf. Compare the colour of the surfaces. Note. — When two or three other lessons have been given of the same kind the teacher may point to the following general conclusions. (1.) Leaves are of two kinds, simple and compound. Simple leaves are those which have one blade on the footstalk. Compound leaves are those which have two or more blades, each with a separate footstalk, but all joined to one common footstalk. (2.) The under surfaces of leaves are usually lighter in colour than the upper surfaces. (3.) All leaves have veins which proceed from the footstalk, but they are arranged in different ways in different leaves. (4.) The margins or edges of leaves are either smooth or out and notched in various ways. (6.) Leaves vary in shape, and size, and colour, and in various other ways, so that the leaf of one kind of plant can always be distinguished from the leaf of another kind. 192 NATURAL HISTORY OBJECT LESSONS. LESSON XIII. The three lessons which follow — on Starch — are intended to show the different treatment of the same subject for children of different ages. STARCH I. (for infants). Fob, illustration : starcli in powder and in sticks, a little powdered sugar, salt, chalk, flour, a large glass of water, and a muslin bag. Apparatus for " making " starcli, a piece of linen or calico, and a flat- I. Properties. Call attention to colour ; compare with other substances, such as powdered sugar, salt, and chalk. (1) for colour, (2) for taste, (8) for solubility in cold water, (4) for feeling when pressed between the fingers. Show how starch can be distinguished by touch. Next show the efiect of boiling water on starch. Mix a little with cold water, and then pour in boiling water. From this illustrate the " starching " of linen, and thus educe one common use. Treat arrowroot with hot water, to show that this sub- stance is really starch. II. Whence and how Obtained. Mix a little wheaten flour into dough, put the dough in a stout muslin bag, and knead the dough under water. The water soon becomes milky with starch. BPJiClMEN LESSONS. 193 LESSON XIY. STARCH II. (for junior scholars). For illustration : a potato, a little wheaten-flour, corn-flour, arrow- root, and sago ; a glass of -water and a muslin bag, a piece of new calico, and a little British, gum. I. Its Preparation. (1.) Cleanse, peel, and rasp a potato, place in a muslin bag, and knead it with the thumb and fingers under water, in a glass vessel. The children will note the milky ap- pearance of the water. This is caused by the tiny particles of starch. After a long time it settles down to the bottom of the vessel, and may be collected by filtering, or by pour- ing ofi" the water and gently drying. (2.) May be separated from wheaten flour as described in the last lesson. II. Its Properties. The more common properties may be gathered from the children by observation and simple experiment. It is a brilliant, white, granular powder, often sold in the shops ia broken sticks ; but these may easily be reduced to powder. "When passed between the fingers starch gives a peculiar, harsh feeling, and it makes a crackling sound. It is heavier than water ; is quite insoluble in cold water. Mixed with hot water it swells into a jelly-like mass, and is used in this state for " starching " linen. The starch grains are really little bags containing starch, too small to be seen except under the microscope. Hot water causes these bags to burst, and set the contents free. When we evaporate the water from a solution of salt or sugar we recover the salt or sugar, but this is not the case with starch. Once mixed with hot water, or heated in water, the beautiful N 194 NATURAL HISTORY OBJECT LESSONS. white grains can never be recovered again. Why P The sacs holding the starch are all broken to pieces. When baked at a moderate heat in an oven starch becomes soluble in cold water, and when mixed with water forms a kind of gum called British gum. III. Kinds and Uses. (1.) Potato, wheat, and rice starch are used chiefly for laundry purposes, and for making British gum. The latter is used in large quantities in the manufacture of paper and of cotton goods, for sizing and stiffening. Compare "writing" with "blotting" paper. The latter is porous, and absorbs the ink ; in the former the pores are filled up with British gum. Rub a piece of new calico, a white dust is detached ; this is the gum used in stiffening, and for giving a ghss. British gum is also the chief ingredient in the adhesive gum of envelopes and postage- stamps. (2.) The starch from maize or Indian corn is called "corn- flour," and is used for making puddings, &c. (3.) Arrowroot and sago are nearly pure starch. Arrow- root is obtained from the root of a plant, sago from the pith of the sago-palm. LESSON XY. STARCH III. (for senior scholars). Sketch of magnified starcli grains, a few peas dry and soaked, a few sprouted grains of wheat, and a little iodide of potassium. I. Storehouses for Starch. Starch is one of the three chief products of "plant factories" (see Lesson LXVIII). It is found more or less abundantly in every plant. It is the chief form in which the food for the SPECIMEN LESSONS. 195 future use of the plant is stored up. It is stored in immense quantities in seeds, especially the cereals, and in potatoes ; and all our vegetable food contains more or less of it. We must look on starch, then, not so much as an article of utility in the laundry or manufactory ; but as the important article of food as well for plants as for animals. Call attention to the sketch on blackboard of starch- grains, showing the form in which the starch is stored, viz. in granules in cells. Show also that these granules take different forms and sizes in different plants, so that a mere glance at the granules under the microscope is sufficient to determine from what plant the starch was derived. If a few grains are placed under the microscope and a drop of sulphuric acid be added the grains swell up and burst, showing that each in its dry state is a kind of bag contracted on its contents. A grain may be compared to a dry, wrinkled pea, and the swelling may be compared to the swelling of peas when soaked in water. II. Chief Properties. The first property of starch is its power of combination with water at a high temperature to form a thick, gelatinous mass. Heat has the same effect on starch as sulphuric acid, provided water is present. The little sacs swell and burst, and their contents combine with the water. Hence it is that soft liquid mixtures of starch become converted by boiling or baking into consistent puddings. Were it not for this property of starch there would be no puddings. The second property of starch is its easy conversion into sugar. Without this property, given the puddings they would be useless, because indigestible. Although the plant- food is stored up in the form of starch it is not used in this form, but as sugar. As the seed begins to sprout the starch begins to change to sugar. Instance, bread from the flour of sprouted wheat is sweet. In the process of making malt, barley 196 NATIJEAL HISTORY OBJECT LESSONS. is made to germinate by heat and moisture, and the starch is converted into sugar. Similarly in the animal kingdom the starch is converted into sugar before it becomes useful as food. In the saliva prepared in the salivary glands of the mouth there is a peculiar substance known a.s,ptyaUn. This ptyalin possesses the property of converting starch into sugar. This becomes mixed with the food during mastica- tion, and the process of converting starch into sugar begins in the mouth. The third property of starch is one which enables its presence to be detected. Starch is always coloured blue by iodine. To a few grains of iodide of potassium dissolved in a tumbler of water add a single drop of any kind of starch. The mixture becomes blue immediately. III. Uses. In this lesson the teacher may pass lightly over other uses and deal with starch as one of the chief foods for keeping up the natural heat of the body, and for supplying the force necessary for movement and work. As to how far the teacher m ly pursue the subject must depend on the knowledge the children have previously acquired ; but at least they may learn so much of the chemistry of starch as a food as may be found in any one of the numerous little text-books on domestic economy found in every school. LESSON XYI. THE HORSE. Foe illTistratioii, pictures of horse and donkey. The special points in the general appearance and structure of the horse to which the attention of little children should be drawn are ; — SPECIMEN LESSONS. 197 I. The Skin. This is thick and covered with hair. Hair becomes much thicker as the winter comes on. Much of it falls off in the spring. Some owners clip their horses, to make them look nice and smooth. They should then be protected with cloths. Skin makes thick leather for soles of shoes. II. The Head and Neck. The neck has a long mane of hair, and the head has a tuft on the top. The eyes are large, and so placed that the animal can see on each side as well as the front. The ears are small and pointed ; they show the feelings of the horse. The horse is said to " prick up " his ears as a sign of attention, or when he is expecting his food. A vicious horse throws his ears back ; a frightened horse extends them forward. III. The Tail. The tail is thick and short and pointed, but covered with long coarse hair, which sometimes reaches down to the ground. People sometimes cut the tail short ; but this is not kind, because it prevents the animal from whisking away the flies which tease it. IV. The Teeth. If the teeth of the horse were arranged like ours we could not put the " bit " in his mouth. Between ihe front and the back teeth there is a long space ; the bit fits into this space. V. The Hoof. The hoof is large, solid, and round, made of a kind of horn, like the nails of our fingers. [See Fig. 100, Part I.] They can be cut without hurting the animal, as we cut our nails. But if we cut too deep it gives great pain, just as when we cut our nails too deep. The hoof grows as fast as it wears out, but the domestic horse is provided with iron shoes, to preserve the hoofs on the hard roads. The 198 NATURAL HISTORY OBJECT LESSONS. smith takes care not to drive the nails into the " quick,'' the horse would be lamed. Compare the donkey with the horse. LESSON XVII. THE COW AND THE SHEEP. Articles for illustration : cow's or sheep's hoof, skull, cow's hair, wool, horas, and any manufactured articles. This lesson may take the form of a comparison between these animals ; first as to general structure and habits, and secondly as to special uses, alive and dead. I. General Structure and Habits. The points of likeness to which the attention of the chil- dren should be directed are the cloven hoof on each foot, the absence of teeth in the front of the upper jaw, and the presence of the hard pad in their place, the horns, and the practice of " chewing the cud." Explain " chewing the cud." The food is swallowed into a large bag without chewing. When the animal is at rest this is brought back through a second stomach a little at a time, properly chewed, and then swallowed into the third stomach, whence it passes into the fourth, the true stomach. The points of difference may be confined to the covering of the skin, the tail, the size of the animal, and the surface of the horns. The covering of the cow consists of short hair, like that of the horse ; that of the sheep of long, twisted hair, which we call " wool." The wool forms a very warm covering. Left to itself it would come ofi' in the early summer, and a new fleece take its place by the beginning of the next wiater. The tail of the cow is long, covered with hair, like SPECIMEN LESSONS. 199 the skin, but has a tuft of longer hairs at the end. That of the sheep is also long, but covered with wool. In this country the tails of young lambs are often cut off. The horns of the sheep, when present, are always rough and knotty on the surface ; those of the cow are smooth. II. Uses. The skin. — That of the cow makes thick leather, that of the calf thin leather for " uppers." Many kinds of leather are made from sheep-skins, such as morocco, kid, and wash leather. The hair. — Cow's hair is used in mixing mortar for plaster- ing, especially ceilings. Wool is used for making all sorts of " woollen goods." The flesh. — Used for food ; some of the fat for tallow. The milk from the cow is a most important article of food ; butter and cheese are made from it. Sheep's milk is used in some countries. LESSON XVIII. HONEY AND WAX. A PIECE of honey-comb with the honey (if sufficient for each child to have a small piece, so much the better), and any articles made of wax should be obtained for this lesson. I. Honey-comb. Let the scholars examine a piece of " comb " from some of the cells of which the honey has not been removed. Call attention to : — (I.) The cells, their size, shape, and wax walls. (2.) The honey, its semi-fluid state, colour, taste. The cells are made and the honey is placed in them by bees. Where do the bees get the wax and the honey ? 200 NATURAL HISTORY OBJECT LESSONS. II. Honey. Bees collect the sweet juices from the flowers, and some- times from leaves, by means of their long tongues. The tongues are, of course, very small ; but little tufts of hair are set on them, and by means of these the juices are swept up, and then carried by the tongue into the mouth. From the mouth they are passed, not into the stomach, but into a little bag within the body, which is called the honey-bag. When this bag is full the bee flies oS' to the hive. Here it is carried from the honey-bag back into the mouth, and thence placed in the prepared cells for winter use, or given to feed their friends, who, being at work in the hive, cannot find food for themselves. The most curious point about the honey is the change which takes place in the honey-bag. The flower juices go into the honey-bag as sweet juice, but what comes out is honey, different in colour, flavour, and smell from the sweet juice which was put in. III. Wax. The wax for making the cell-walls is not collected ; it comes from the body of the bee. Between the rings of the body on the under surface we find six little flaps, these cover six little pockets made of thin skin. The bees must rest while these pockets are being filled with wax. They are said to hang in festoons from the top of the hive for twenty-four hours, and at the end of this time the wax can be seen forcing the pocket-flaps open. This wax is taken from the pockets by other bees, in bits, which they knead in their mouths like a mason works his mortar, or a glazier his putty. It comes from the mouth as a tiny white ribbon, and with this pre- pared wax other bees make the cells. Large quantities of bees' -wax are used for making the best candles ; also for artificial flowers and fruit. But for these purposes it has to be cleansed. The empty comb is first melted in boiling water and then strained through hair bags. SPECIMEN LESSONS. 201 In this state it is yellow. When wanted of a nice white colour it is cut into shavings and laid on canvas in the open air. The properties of wax may be gathered from the children. LESSON XIX. IVORY. The articles required for this lesson are rough and polished ivory and hone, and beyond these, as many specimens of tusks and articles made of ivory as the teacher can command. Also pictures of tusk-bearing animals. I. Natural History. Ivory is the name given to the dentine of teeth large enough to be available for industrial purposes. The incisor teeth or tuslcs of the elephant, hippopotamus, walrus, and narwhal furnish pretty nearly the total supply. [Show pictures of these animals. Show incisor teeth. Refer to teeth of Rodents.] The tusks are hollow at the base and gradually become solid towards the smaller or pointed end. Elephant tusks yield the iinest ivory. The tusks vary in length from a few inches to as much as ten feet. They occasionally weigh as much as 150 lbs. or 160 lbs., but the average is from 10 lbs. to 20 lbs. The tusks of the Indian elephant are much smaller than those of the African, and it is only in the latter species that the female as well as the male is armed with these formidable weapons. A small number of shed tusks are picked up by the natives for sale, but the greater number are obtained by hunting and destroy- ing the animal. Large quantities of tusks of an extinct long-haired ele- phant — the mammoth — are found in the frozen soil near the 202 NATURAL HISTORY OBJECT LESSONS. rivers in Northern Siberia. The ivory from these tusks furnishes material for Russian ivory-turners. The quality of the ivory, however, is inferior, and but little used in this country. The ivory from the tusks of the hippopotamus is harder and whiter, and is less prone to turn yellow than elephant ivory. It was at one time much used by dentists for making artificial teeth. II. Properties. Compare polished plates of ivory and bone. The former is distinguished by curved lines of great regularity and beauty. The transverse section of an elephant tusk shows these streaks running from the centre to the circumference, not in straight, but in curved lines turning right and left and thus crossing each other. [Compare with the " engine- turned " watch-case. J Ivory may also be distinguished from bone by the closeness of its grain, and by the beautiful polish which it takes. In thin plates ivory is translucent, more so than paper of the same thickness. It is elastic, very hard, and less liable to crack than bone. III. Uses. It is owing to its strength, durability, hardness, and beauty when polished, that ivory is carved or turned into so many articles, useful and ornamental. The children will be able to enamerate many articles made of ivory. Handles of knives and forks, organ and pianoforte keys, combs, backs of hair-brushes, paper-knives, napkin-rings, and thin sheets for miniature painting, and for writing tablets are among the articles of utility. IV Vegetable Ivory. This substance, which resembles real ivory and Is some- times used as a substitute, is taken from the nut of a species SPECIMEN LESSONS. 203 of palm growing in South America. The nut at first con- tains a sweetish milky fluid which gradually hardens as the nut ripens until it becomes what is known as vegetable ivory. Note. — In 1883, 13,597 cwt. of ivory teeth were imported, valued at £640,000, and 24,628 cwt. of vegetable ivory, valued at £18,000. The vege- table ivory is brought mainly from South America. LESSON XX. SEEDS AND SEEDLINGS. I. I. Preparation. With a little preparation this lesson may be made exceed- ingly interesting and instructive. The first object is to show how seedlings are developed from seeds, and of what parts the seedlings consist. Fill a pot with fine clean sand, and plant a score or more of the common field bean half an inch deep. Moisten the sand and set aside in a warm room. Care must be taken that the sand does not become dry. It is a good plan to cover the pot with a sheet of glass to pre- vent evaporation. In a few days the seeds will begin to sprout, that is the seedlings will begin to grow. [The time necessary for germination depends on the temperature. At 55° or 60° Fah. the leaves will be seen emerging from the sand in six or seven days. Old seeds require more time than new.j Now take another pot of sand and plant a few more seeds, and when these begin to germinate plant a third set. In about three or four weeks all the seedlings will be growing. To complete the set soak a few more seeds for twenty- four hours before the time fixed for the lesson and the preparation is complete. II. Examination and Comparison. The plants must be carefully removed from the sand and 204 NATURAL HISTORY OBJECT LESSONS. placed on the desks in front of the scholars, who will arrange them under the guidance of the teacher in a series, from the largest to the smallest, the latter of course being the soaked seeds which have not germinated. The children will now carefully examine the plants, and, guided by questions from the teacher, will discover for them- selves all the points of difference and resemblance. Firstly, look at the soaked seeds. They split lengthwise into halves forming fleshy lobes,* and show a little cone- like hodj between them but close to one edge. Now take the plants which have made the least growth, and note what changes have taken place. The lobes which make up the bulk of the seed are greenish, fleshy seed-leaves. The little cone-like body has thrown out roots from the pointed end, and the first green leaves from the opposite end, and the part between forms the stalk. In a similar way examine the other two sets, with a view to bring out the changes which have taken place by growth, and to compare and match the parts which correspond in the plants, and in the seeds. III. The Lesson. The lesson to be impressed on the children is that the young plant is laid up in the seed, and that it needs only warmth and moisture to start it into active life. LESSON XXI. SEEDS AND SEEDLINGS. II. I. Preparation. The next step is the comparison of seedlings of different plants. Take, for example, the seedlings of the pea, oak, and * If the haricot or French bean is used the seed-lobes will be carried to the surface and above with the stalk. SPECIMEN LESSONS. 205 Indian-corn. The sets may be prepared by the method shown in the last lesson, but the children will probably be interested to see them grown in another way ; for instance, upon wet paper, or in cocoa-nut fibre, or on a damp sponge. For paper planting use thick blotting-paper on a sheet of glass. Moisten with warm water, spread the seeds, and cover with another sheet of the paper. The whole must be kept moist and warm. [The interest in the lesson will be further enhanced if the teacher will take the trouble to germinate two or three acorns and a grain or two of Indian- corn a fortnight or three weeks before the first of the paper plantings. Immediately the seeds have sprouted suspend them carefully by a thread, or upon a perforated card, over water in a clean glass bottle or tumbler, so that the roots may be beneath the surface of the water, and the seed-leaves above. The roots will spread through the water and the leaves will expand in the air.J II. Examination and Comparison. The seedlings of the pea, in the various stages of growth, may be examined first, and compared with the embryo in the seed. It may next be compared with the seedling of the bean. The main parts correspond ; but in the pea the seed- leaves remain within the husk or skin of the seed. The tiny embryo lengthens just enough to get out of the husk, and then the roots issue from the lower end of it, and a strong leafy stem is developed from the upper end. The seed- lings of the acorns may next be examined, and compared with those of the pea and bean. A more important comparison is that between the pea, bean, or acorn, and the Indian- corn, and the special points to note are — (1.) Two seed-leaves in the bean, pea, and oak. One seed-leaf in the Indian-corn. (2.) The leaves of the bean, &c., unfold in pairs. 206 NATURAL HISTOET OBJECT LESS0N8. The leaves of Indian-corn unfold singly and on alternate sides. (3.) The roots of the bean, &c., consist of a main stem and branches. The roots of the Indian-corn form a cluster of hair-like fibres. (4.) The veins of the leaves of the bean, &c., are branched and form a network. [See page 36.] The veins of the leaf of the Indian-corn run from the base to the point side by side. [See page 36.] This comparison of the veins can be best made in the specimens of larger growth. III. The Lesson. The lesson to be drawn is that the seeds of some plants enclose two seed-leaves, while others enclose only one seed- leaf. And the children may be told that with the exception of ferns, sea- weeds, and mosses, all the plants in the world may be arranged in two classes : those with two seed-leaves and those with one seed-leaf. The leaves of the former have branched veins in a network, those of the latter are straight- veined, the veins running side by side. To the first class belong most of the plants of our own country. Plants of the second grow mostly in hot countries ; but we have specimens in the grass, the corn, and the onion. LESSON XXII. OLIVE OIL. POE illustration provide specimens of the oil, and the pickled fruit ; also a picture of the tree. I. Properties of the Oil. (To be shown by experiment.) (1.) Weight. — Pour a few drops on water in a bottle ; SPECIMEN LESSONS. 207 shake well ; it breaks into tiny drops whicli float in the water. On standing, these quickly ascend to the surface, forming a thin layer of oil. Olive oil is the lightest of all the fixed oils. (See page 69.) (2.) It is inflammable and burns beautifully in a spirit- lamp through a wick. It is too expensive, however, to be used for lighting purposes. (3.) It becomes solid at a temperature considerably above the freezing-point of water. Stand a little in a test-tube in melting ice, it soon becomes solid. (4.) Other properties such as its semi-transparency, and softness to the touch, children will discover for themselves. II. The Tree and its Fruit. (For description see page 69.) Cut in pieces a few of the pickled unripe fruit to show the pulp whence the oil is obtained, and the stone within. Taste the pulp : it is oily, rough, and bitter. Show how the oil is obtained by pressure. Three qualities are obtained. The first by gentle pressure in coarse bags from the best hand-picked fruit. This, the best and purest oil, is called virgin oil. A second quality is obtained by warming the pulp, and then applying gentle pressure. This does not, however, extract all the oil, and a third and inferior quality is produced by boiling the crushed pulp in water. ni. Uses. In countries where the olive-tree grows the purest oil takes the place of butter and cream. In our own country it is chiefly used in cooking, and for salads. The commoner kinds are used in the manufacture of soap. 208 NATURAL HISTORY OBJECT LESSONS. LESSON XXIII. LIBER. Articles for illustration. — As many specimens of inner bark as the teacher is able to obtain : but common bast, raw hemp, and raw flax must be included. Also specimens of manufactured goods. I. "What is Liber? Take twigs of the common lime-tree, or stalks of nettles, or any convenient stems from which the children may dis- cover the tough, stringy inner layer of bark. This inner layer is called liber, and sometimes hast or hass. Before the invention of paper some kinds of inner bark were used as writing-material. Hence its name liher, or book. Or it may have taken its name from the fact that the inner bark con- sists of thin layers like the leaves of a book. Liber fibres are long and tenacious, and in some plants they are sufficiently tough, pliant, and strong to be put to a variety of useful purposes. The coarser kinds are made into rope, twine, netting, mats, sails, and so on. The fine kinds are woven into the finest materials for weariDg apparel, &c. II, Kinds of Liber. (1.) Bast. — This is the inner bark of the lime-tree, and is used in Russia for the manufacture of mats, ropes, shoes, hats, and other articles. Several millions of Russian mats are imported into this country every year. They are used chiefly for packing furniture for removal, and for covering young plants to protect them from the frost. [The teacher will probably be able to show the children one of these mats.] (2.) Flax. Show how the flax fihres are separated from the hard parts of the stalk of the flax-plant, and how they are prepared for spinning (See page 82.) Show specimens of raw flax, and of the manufactured goods, and compare the latter with cotton goods. SPECIMEN LESSONS. 209 New Zealand Flax is prepared from a sedge-like plant growing in marshy situations, and near the sea-coast. (3.) Hemp. — To be dealt with in the same way as flax (see page 84), and the manufactured goods compared with both linen and cotton cloth. Manilla hemp is a fine kind of hemp prepared from a species of plantain. (4.) Other hinds. — A fibre much superior to that of flax or hemp can be obtained from a kind of nettle which grows in India. In gloss and fineness it resembles silk. The difficulty and cost of preparation, however, prevent its general use. The people of India manufacture very curious sacks from the liber of a tree common in some parts of the jungles. " A branch is cut corresponding to the length and breadth of the sack wanted. It is soaked a little, and then beaten with clubs until the liber separates from the wood. The liber in the form of a sack is then turned inside out, and the wood is sawn ofi', with the exception of a small piece left to form the bottom of the sack. These sacks are in general use among the villagers for carrying rice." A very beautiful kind of liber is obtained from a tree which grows in Jamaica. When the layers are separated they have the appearance of delicate lace. Hence the tree is called the vegetable lace tree. LESSON XXIV. KINDS OF ANIMALS. MAMMALS ANT BIRDS. (A first lesson in classification.) I. Introduction. Ask the children for names of animals which walk, fly, crawl, and swim. Write the names as given on the black- 210 NATURAL HISTORY OBJECT LESSONS. board, adding such otliers as may be necessary for the teacher's purpose. Suppose the written list to be as follows : — Sorse, crah, snake, hat, sparrow, eagle, coto, owl, cat, whale, duck, herring, seal, robin, s'rpent, snail, sheep, worm, mackerel, toad. II. First Step. Direct the children to arrange these animals in four classes according to the method of locomotion, and write on the blackboard thus : — 1.9^ Class. 2nd Class. ^rd Class. Wi Class. Walking Animals. Flying Animals. Crawling Animals. Swimming Animals. Horse Bat Snake Whale Crab Sparrow Serpent Duck Cow Eagle Snail Herring Cat Owl Worm Seal 8heep Robin Toad Mackerel. We have thus grouped together into classes certain animals as they are alike in one particular — the way in which they move about. The children may add to the number. But it does not seem natural to place the crab and the horse together, or the worm and the toad, or the duck and the herring. The fact is, in grouping animals together it is not satisfactory to look to one particular only, but to many ; and our great aim should be to place together those which are alike in the greatest number of particulars. III. Second Step. Now let us look a little more closely at the animals which we have placed in the four classes. 1. The walking animals. — Look at the covering of the skin. The horse, cow, cat, sheep are all covered with hair, for fur and wool are but special kinds of hair. The crab has an SPECIMEN LESSONS. 211 outside shell and no hair. Children all know that the horse, cow, cat, and sheep have bones inside their bodies, and I daresay most of them know that the crab has no bones inside. Here is a second important particular in which the crab is unlike the other walking animals. Again, the horse, cow, cat, and sheep feed their young with milk, which they make in their own bodies. The mother crab lays eggs, and does not attend to her young at all. Lastly, if we could feel the bodies of these animals we should iind that those which feed their young with milk have warm bodies, like our own. The crab, when living, feels cold to the touch. So we see that the horse, cow, cat, and sheep are alike, not only in the way they move about, but also in four other important particulars. {a.) The hairy covering of the skin. (p.) Having internal bones. (c.) Feeding their young with milk. [d.) Having warm bodies. The crab has none of these, and therefore we strike it out from our First clans. 2. The flying animals. Now look at the Second class. The covering of all the birds consists of feathers, that of the bat is a hairy skin. Birds lay eggs, and when the young are hatched feed them with solid food. The bat suckles her young, like the cat. AU the animals in the second class are alike in having in- ternal bones and warm blood. We see, therefore, that the birds are all alike in — (a.) The feather covering, (b.) Having internal bones. (c.) Laying eggs. (d.) Having warm bodies. But the bat, though like the birds in two of these par- ticulars, is like the First class in all except the method of locomotion. We must therefore promote the bat to the Mrst class. Our First and Second class will stand thus : — 212 NATURAL HISTORY OHJECT LESSONS. First Class. Second Class. Horse. Eagle. Cow. Sparrow. Cat. Eobin. Sheep. Owl. Bat. Mammals. ■ Birds. (a.) Have internal bones. {a.) Have internal bones. \b.) Have warm bodies. (J.) Have warm bodies. (c.) Hairy covering to skin, (c.) Feather covering to skin. {d.) Suckle their young. {d.) Donot suckle their young. The above should be written as the final summary, and the children should be asked to add to the classes, especially the first. The First class are named Mammals, from mammm, the glands which secrete the milk. LESSON XXV. KINDS OF ANIMALS. REPTILES AND FISHES. (A second lesson in classification.) In this lesson we have to consider the Third and Fourth classes, viz., crawling and swimming animals. [See last lesson and write the names on the blackboard.] 1. The crawling animals. First as to their coverings. The snake and serpent have scaly coverings, the toad has warts on a naked skin, the snail and worm have naked, slimy skins. The snake and serpent and toad have internal bones, the snail and worm have none. All lay eggs except some of the snakes and serpents, and all have cold bodies. SPECIMEN LESSONS. 213 From our Third class we reject the worm and snail because they have no internal skeletons. As we shall learn by-and- by, there are other ijnportant differences in their structures. 2. The swimming animals. The children will answer at once that the duck should be promoted to the class of Birds. There will not be much difficulty either in transferring the seal to the Mammals. But the whale is so like a fish, and is so often commonly considered as a fish, that the children will need to be told why it is a mammal, and not a fish. It suckles its young, which no fishes do ; and it has warm blood, which no fishes have ; and it is therefore as much a Mammal as a horse or a cow. The herring and the mackerel have their skins covered with scales. They have, as every child knows, plenty of internal bones. They do not suckle their young, their bodies are cold to the touch ; and there is another important par- ticular in which they differ from all the animals which we have placed in the other classes, they have gills for breathing instead of lungs. We may now give our Third and Fourth classes their proper names, and arrange all the animals in their proper classes. The creeping or crawling animals are called Reptiks,* a word which means creeping. The Fourth class are Fishes. Thus we have : — Mammals. Birds. Reptiles. Fishes. Horse. Sparrow. Snake. Herring. Cow. Eagle. Serpent. Mackerel. Cat. Owl. Toad. Sheep. Eobin. Bat. Duck. Whale. Seal. • This is not a good name, because some of the reptiles do not crawl. 214 NATURAL HISTORY OBJECT LESSONS. The children should be encouraged to name other animals belonging to the four classes, and give their reasons for placing in the particular class. Of mammals, birds, and fishes they will know plenty, but in the case of reptiles the teacher will probably have to lend his assistance. The chief characteristics of the four classes arranged in a tabular form will be of considerable service in future lessons. Mammals. Possess internal skeleton. Breathe by means of lungs. Have warm blood. Skin covered witb hair. Suckle their young. BiBDS. Possess internal skeleton. Breathe by means of lungs. Have warm blood. Skin covered witb featheis. Lay eggs from which \ouni5 are hatched. Reptiles. Possess internal skeleton. Breathe by lungs or gills. Have cold blood. Skin covered with scales or naked. Lay eggs from which young are hatched. Pishes. Possess internal skeleton. Breathe by gills. Have cold blood. Skin covered with scales. Lay eggs from which young are hatched. LESSON XXVI. KINDS OF ANIMALS. MAMMALS. (A third lesson in classification.) I. Introduction. Question the children on the meaning of the word mammal, and on the chief distinguishing features of mammals as given in Lesson XXIV. In one of these particulars, the possession of a bony skeleton, they are like all the classes we have dealt SPECIMEJSI LESSONS. 215 with. They are like birds also, in having warm bodies. They stand alone in suckling their young, and in having the skin covered with hair of some kind. Now, as in the first lesson on classification, let the children name all the animals they can which belong to the class of mammals. Write the names as given on the blackboard, and add any others as may be necessary for the lesson. Suppose the list to be : horse, cow, cat, sheep, dog, elephant, goat, deer, monkey, mouse, hat, rat, rabbit, hare, hedgehog, mole, whale, seal, ant-eater, kangaroo, gorilla, lion, tiger. II. Orders of Mammals. The teacher may now guide and assist the children to arrange these animals in something like order ; and as the groups or orders are formed, he may name other animals belonging to the same group, and show pictures of any which are unfamiliar. 1. Which animals use all the feet as hands ? The monkey and gorilla. Put these together and add the baboon. The gorilla is an ape, and We place all Monkeys, Apes, and Baboons in one group, and call it Four-handed (Quad- rumana). 2. Which animals have wings, and fly through the air ? The bats. The bats form a separate group, the Wing-handed (Cheiroptera). They are so called because the hand is made into a wing. 3. Which animals feed on flesh ? The cat, dog, lion, tiger, seal. These are put into another, and QsiMeA. flesh-eaters (Carnivora). The leopards, bears, jackals, and hyaenas also belong to this order. 4. Which animals feed on insects ? The mole and the hedgehog ; they have teeth with sharp points for crushing. With the Shreivs, they form the order of Insect-eaters (Insectivora). 5. Which animals have broad, cutting teeth in front, with 216 NATUEAL HISTORY OBJECT LESSONS. which they gnaw ? The mouse, rat, rabbit, hare. These are gnawers (Rodentia). To this order belong an immense number of animals. The beaver, squirrel, field-vole, porcu- pine, and prairie-dog are members of this order. 6. Which of the animals live in the water ? The whale. The dolphin and porpoise are put in the same group with the whale, and the order is called Whale-like (Cetacea). 7. Which of the animals " chew the cud?" The cow, sheep, goat, and deer. They form the order of cud-chewers (Ruminantia). 8. Which of the animals have no teeth ? The ant-eater. The sloths are placed in the same group with the ant-eaters. They are called toothless animals (Edentata). [As a matter of fact the sloths have back, but no front teeth.] 9. Which of these animals have very thick skins ? The horse and the elephant. The pig, donkey, hippopotamus, tapir, and many other animals belong to the order of thick- skinned animals (Pachydermata). 10. One animal is left, the kangaroo. The kangaroo has a pouch in front of the body, in which it carries its young. All animals possessing these pouches are pouched animals (Marsupialia). LESSON XXVII. CHEWING THE CUD. Illttsteatb by diagrams and pictures. I. Introduction. The teacher may very well introduce this lesson with a conversation with the children on the way in which domestic animals take their food into their mouths, and then chew it. If the food be small, or in a liquid form, the cat and dog SPECIMEN LESSONS. 217 lap it up with the tongue ; if it consists of flesh they cut it to pieces with the side teeth, moving the lower jaw up and down only with a jerking motion. There is no grinding of the food. The horse collects loose food with his delicate lips. Grass he bites ofi" with his front teeth. Holding the grass as in a vice he gives a jerk of the head and off it comes. Then he grinds it with his large molars, the lower jaw having a side-to-side motion for the purpose. The cow collects her food with her long tongue. In eat- ing grass a sweep of the tongue brings it within the lips. Here it is taken hold of and held between the front teeth of the lower jaw and the hard pad which takes the place of the teeth in the upper jaw ; a jerk of the head tears it off. n. Collecting the Food. Now, if you look at a horse and a cow while feeding you will see that the cow feeds much faster than the horse. She chews her food scarcely at all, and swallows it very quickly. Children, no doubt, will have been told that to swallow food without properly chewing it is not good, neither is it. What of the cow then ? The cow, sheep, goat, deer, and many other animals collect their food and swallow it into a larffe bag (called a stomach) without much chewing ; and when they have collected a sufficient supply they lie down, and then quietly set to work to chew it pi-operly, a little at a time. This is called " chewing the cud." III. Chewing the Cud. Watch a cow, a sheep, or a deer in the act of chewing the cud. The animal gives a sort of hiccup, then slowly grinds away for a certain time, and then swallows the chewed food. After a second or two, another hiccup follows, and the grind- ing begins again, and this process is repeated till all the food is masticated. All the animals which chew their food in this way are called Ruminants, a word which means " chew- 218 NATURAL HISTORY OBJECT LESSONS. ing the cud." Euminants are all provided with a special kind of stomach adapted to the purpose of rumination. The illustration (for blackboard) will explain the structure. [See Fig. 1 Appendix.] a is the gullet up and down which the food passes. b is the paunch, a large bag for storing the unchewed food. c is the honey-comb, so called because the lining consists of cells like the honey- comb of the bee. d is the manyplies, so called from the many folds or plies in the lining. e is the reed or true stomach. The process of rumination seems to be thus : — When the animal has ceased feeding, and wishes to chew, a little of the food is passed from the paunch into the honey- comb, and thence forced into the mouth. Here it is mixed with the saliva and properly masticated, and then flwallowed again. But this time it does not go into the paunch or honey-comb. It is in a semi-fluid condition and passes along the manyplies and into the true stomach, where it is properly digested. In the camel and llama the manyplies is wanting, and the cells of the honey-comb are much enlarged and made receptacles for holding water. They are closed in front, that is internally, but there exists an opening which can be opened or closed at the wUl of the animal. Other and smaller cells of the same kind are also found in the walls of the paunch, and these also serve for the storage of water. Note. — An interesting lesson to follow the above may be given on the camel. The special points to be noticed are the water-cells, the structure of the feet — spreading pads taking the place of hoofs, the callous pads of hardened skin on the leg joinis and chest, the peculiar structure of the nottrilt for keeping out the sand, and the teeth in front of the upper jaw. SPECIMEN LESSONS. 219 LESSON XXVIII. HORNS AND THEIR USES. Illusteatb with diagrams, a cow's or other horn, and articles made from horn. Let the children name all the animals they know which possess horns. Write the names on the blackboard. It will be found that nearly all the horned animals belong to the "ruminants." [Explain.] Horns are of two kinds, and these kinds differ in character and properties, and in their mode of growth. I. Homy Horns. [Permanent horns.) The horns of oxen, sheep, goats, and antelopes are all hollow. They are formed of a material very much like the nails of our fingers, which we call horn from its source. These horns grow during the whole life-time of the animal, and are never shed * except by accident. If the horn of a cow or an ox gets knocked off, as it occasionally does, a bony core is seen projecting from the head like a small cone ; on this the real horn was fixed. The core is covered with a very sensitive skin full of nerves and blood-vessels. We may cut the real horn without causing pain or injury, just as we may cut our finger nails at the edge ; but if we cut the skin of the core it causes intense pain, such as we feel in our fingers when we cut the nails too close. The horns of ruminants are occasionally straight, but more often they are bent or curved, and not unfrequently twisted, and they are of all lengths up to five or six feet. II. Bony Horns. (Deciduous horns.) The horns of the various kinds of deer are formed of a kind of hard bone, and they fall off and are renewed every * With one exception, the Americau antelopes shed their horns. 220 NATURAL HISTORY OBJECT LESSONS. year. With the single exception of the reindeer, the horns are confined to the males. The method of growth of these horns is curious and interesting. Take the common red stag as an example. The horns are shed early in the year. Soon two little knobs may be seen to occupy the place of the future horns, and they are covered with a beautiful soft, velvety skin. These knobs grow very fast, and very quickly indicate the shape of the future horn. The velvety skin is full of blood-vessels through which the blood courses de- positing animal and mineral matter, and adding to the growth of the horn as it passes along. If the horn be grasped at this time it will be found quite hot. In about eight or ten weeks the horns will have attained their proper dimensions for that year. The blood-vessels of the skin pass through projecting bony rings at the base of the horn, and when the growth is complete these rings thicken and close the blood-vessels. Left without nourishment the skin now shrivels and peels off, or is rubbed off by the animal against the trunks of trees. Although the horns fall off every year, yet the horns of each succeeding year are more fully developed till the animal becomes adult, when the horns are large and long, and divided into numerous spread- ing branches. These bony horns are called antlers. Some of the antlers, like those of the stag or red deer, have cylin- drical branches tapering to a point ; others, like the fallow deer and reindeer, have flattened branches. III. Uses. Horns are used for a variety of purposes ; the bony horns of the deer-tribe chiefly for knife and fork handles ; the horny horns of the ox-tribe for combs, drinking-cups, knife and fork handles, &c. The term horn is usually applied to the soft horn of the ox, sheep, &c. This horn is similar in structure to nails, and hoofs, and claws. It is fibrous, and the fibres are elastic and flexible. Cut into slices it is almost SPECIMEN LESSONS. 221 transparent. [Formerly used for lanterns.] Soaked in hot water it becomes soft, and may then be pressed out quite flat, and stamped and cut into the various articles needed. The tips of the horns being solid are used for making buttons. LESSON XXIX. PARTS OF A FLOWER (outline). Seniok Inpants and Lower Standakds. Any common flowers will serve for tHs lesson provided they are sufflciontly large for the children to see the parts with the naked eye. Each child should be provided with one or two specimens. In this lesson we take the wall-flower and tulip as examples. These flowers come into blossom about the same time in the spring. I. The Wall-flower. The children must be led to point out the parts them- solves, the teacher giving the names only. The flower is set on a stalk. Outside we see four little green leaf-like bodies ; these form the calyx — covering — and each part is a sepal. Then follow /owr more leaf- like bodies, but these are coloured. Together they form the corolla — little crown — and each separate piece is a petal. Inside the corolla we find six little bags set on stalks : four long and two short. These are the stamens ; the bags are the anthers, and the stalks the threads, or filaments. In the anthers we find a kind of dust called pollen. In the centre of the flower we find another organ, the pistil. The pistil is made of the long ovary containing the ovules or young seeds below, and the stigma above. The ovary is two-celled. 222 NATURAL HISTORY OBJECT LESSONS. Show by a sectional diagram (Fig. 2) how the sepals, petals, and stamens are arranged in rings round the pistil as the centre. II. The Tulip. Examine the tulip in a similar way. There are no green sepals. The petals are six, and coloured. Stamens also six, and of equal length. The ovary is short, and contains three cells. III. Comparison. Compare the parts of the two flowers and write on the blackboard thus : — Wall-flower. Tulip. Cal^x = four green se- Cali/x — absent. pals. Corolla = four coloured Corolla* = six coloured petals. petals. Stamens = six — four long Stamens = six of equal and two short. (An- length. (Anthers on thers on stalks.) stalks.) Pistil — Long. Ovary cut Pistil — Stigma on stalk. across shows two long ovary three-celled. cells with ovules in each. Note. — The time of two or three more lessons should be given to the general examination of other common flowera before going into a closer inspection of the anthers, ovaries, ovules, and seeds. • The floral envelope of such flowers as the tulip is called the Perianth, and is supposed to be made up of an equal number of sepals and petals : but the children need not notice this at present. SPECIMEN LESSONS. 223 LESSON XXX. BIRDS' NESTS. IiiLTTSTEATE with diagrams and pictures, and if possible with some specimens of nests. I. General Appearance and Strnctnre. All children know sometliing about birds' -nests, and the teacher should introduce this lesson with a series of questions leading up to the idea that birds need nests in which to deposit and hatch their eggs, and for the comfort and pro- tection of their young. The general shape of the lower part of all birds' nests is that of a broad shallow basin. There are reasons for this. The eggs fall together as they are put in the nest, they do not roll about as they would be liable to do on a level floor, and they are kept close together at the bottom, so that the bird can the more easily cover them and keep them warm during the time she is " sitting." Some birds make warmer nests than others by lining them with hair and wool, and even feathers plucked from their own breasts. There are reasons for this too. Some birds when first hatched have very little covering indeed, and these need the warmer nests. Those which live in cold countries, too, need special protection. It is a remarkable fact that all birds of the same species construct exactly the same kind of nest. Blackbirds and thrushes line their nests with mud ; but the thrush lines this again with fine grasses. Now the thrush never forgets the second lining, and the blackbird never copies the thrush. And, so far as we know, the same kinds of birds have always built their nests in precisely the same manner. Nests are constructed of all sorts of materials — twigs, dried grass, leaves, straw, fibrous roots, moss, lichen, hair, wool, down from flowers, chips of wood, and even of fish- 224 KATDEAL HISTORY OBJECT XtSSOKS. bones. Large birds usually content themselves with a coarser kind of nest ; but the smaller species display great art in constructing their tiny dwellings. The fowl is con- tent to press a hollow with her body in a heap of straw, the ostrich scratches a hole in the sand, the eagle throws together a huge mass of twigs, the ring-dove is content with a few twigs interlaced, and the rooks, a little more particular, line their basket-work nests with root fibres. The nests of most British birds are open above to the sky, a few only are roofed over. Most of them are placed on or among the branches of trees and hedgerows, a few are con- structed on the ground in hollows, and some are laid at the ends of tunnels dug by the bird for the purpose. In other countries many nests are suspended from twigs and leaves. II. Some Varieties of Nests. (1.) Roofed Nesis. — Of roofed nests the most common in our own country are those of the house-martin, but the neatest and the most elegant are those of the long-tailed tit. The house-martin builds her nest under the eaves of houses, where they are often very conspicuous objects. The walls are constructed of mud ; and, just as the plasterer mixes hair with his mortar to make it hold together when dry, so the little bird-mason puts bits of grass, feathers, fine roots, &c., in her building-mud, and for the same purpose. The nest is lined with feathers. The door is left at the side. The nest of the long-tailed tit is fixed in a fork where several branches are thrown off from the same point in the stem, and its situation is the thickest bush. It consists of mosses, wool, hair, and similar substances, bound together with spiders' webs and the silken cocoons of various insects. Outside it is covered with lichen, gathered from the bark of trees ; inside it is lined with soft downy feathers. Some of the finches and the wren construrt roofed nests, but they are not so beautiful as that of the tit. SPECIMEN LESSONS. 225 The magpie builds a large nest, and roofs it over. The nest, which is placed in the fork of a branch high up in the tree, is a network of sticks interwoven with sharp thorns, and lined with moss, and other soft substances. (2.) Hanging Nests. — These are nests hung from the ends of twigs or drooping branches, or even leaves, often over water. They are of every shape and design, but as they are all foreign, we will describe but one — the nest of the tailor- bird. Choosing a convenient hanging leaf, this bird pierces rows of holes along each edge, using its beak as a brad-awl. It then selects a long fibre of some plant, and passing it through the holes, draws the edges of the leaf together so as to form a kind of hollow cone with the point downwards. In this the bird constructs the nest of soft white down, gathered from plants. Should the bird fail to find a single leaf large enough, it sews two together by the edges, and should the nest require strengthening, it sews on another leaf. [The teacher may explain to the children why so many birds suspend their nests in hot countries. Monkeys and snakes are plentiful, and they are fond of eggs.] (3.) Nests in Burrows. — The sand-martin makes a burrow some two or three feet deep, at the end of which to place her nest. She usually chooses a perpendicular cliff of soft sand- stone. The burrow is not quite longitudinal, it slopes a Kttle upward, so that water cannot run in. The nest is very simple — a little dry herbage and soft feathers pressed down. The king-fisher takes advantage of a hole made by some other animal — usually the water-rat — in which to make its nest oi fish-hones, ejected by the bird itself. [Explain that some birds, as the owl and king-fisher, for example, eject through the mouth the undigested parts of the food.] The puffln and the storm-petrel can burrow, but they prefer to take advantage of the tunnel of some other animal. Many other birds take advantage of holes and hollows. P 226 NATURAL HISTORY OBJECT LESSONS. The wood-pecker makes her nest in a hole excavated with her beak in the trunk of a tree ; but she always takes advan- tage of some spot where the wood is soft through decay. Her nest is made of the chips broken off. LESSON XXXI. THE HEDGE-HOG. To be illustrated by pictures, or if possible by a live specimeiii Introduce this lesson by showing why the hedge-hog is so called. It has a snout like a pig, and it frequents, and often makes its home, in hedge-rows. I, General Appearance and Structure. To be gathered from the teacher's description and pictures, or from the specimen. The chief peculiarity in the structure of the hedge-hog is the spiny covering. Instead of being covered with ordinary hair, the skin of the back and sides is beset with spines. These are about an inch in length, hard and pointed, and of a dirty white colour, but marked in the middle by a dark band. The end embedded in the skin moves like the ball in a ball-and-socket joint. The under part of the body is clothed with yellowish white hair. The legs are short and feeble. There are five toes on each foot, and each toe is terminated by a claw. The tail is very short. [Compare with toes of cat and dog.j The teeth are numerous ; the front molars are suitable for cutting purposes, and the back molars for crushing hard substances. II. Habits. We have now to inquire whether the structure of the hedge-hog is in agreement with its habits. The chief SPECIMEN LESSONS. 227 peculiarities of structure are the spines and the teeth. "Why are the spines needed ? Of what special use are they ? How are they used ? Most animals are provided with some means of escape or defence from their foes. The hedge-hog, without its spines, would be but a feeble animal indeed. Its legs are too short and feeble for swift running, and its claws would prove but poor weapons against the fox or the badger. Hence its shield of sharp spines. When disturbed, or when attacked, the hedge-hog rolls itself into a ball, with the head and legs carefully tucked inside, from which the spines then stand out on all sides, like pins from a pin-cushion. When not in use, the spines lie flat upon the body, but the very act of rolling itself up also erects the spines. The organ for this purpose is a broad band of muscle, which passes along the sides, and so round the body, just beneath the skin. The contraction of this muscle draws the skin over the ball and erects the spines. This peculiar action of rolling itself into a ball, and erecting the spines, answers two purposes. It serves as sufficient protection against most of its enemies, and enables it to fall down considerable heights without injury. Very few dogs have pluck enough to make a suc- cessful attack on a roUed-up hedge-hog. The second peculiarity lies in the teeth. Some of these are suited for cutting and tearing, and others for crushing hard substances. Now the hedge-hog feeds on insects, chiefly beetles, with hard wing-cases, and here the crushing teeth are needed. But it is also fond of frogs, mice, snakes, and any young game it may come across, and here its cutting teeth come into play. When in confinement it feeds readily on soaked bread and cooked vegetables. Advantage is sometimes taken of its fondness for insect food to rid kitchens of cockroaches. The hedge-hog makes her home in forests and woods and hedge-rows, and prowls about at night in search of food. The female makes her nest of moss and leaves in cavities 228 NATURAL HISTORY OBJECT LESSONS. under the roots of trees or in hedge-bottoms, and even in rocks and walls. Here she sleeps, with her mate, during the winter, and here she rears her young in the summer. The hedge-hog is easily tamed. It soon loses its fears, and will allow itself to he handled without attempting to roll itself up. LESSON XXXII. WHALE-OILS. Speoimens of train and sperm oils, and of spermaceti, raw and puri- fied, should be provided. Also pictures of whales. I. The Whale. The teacher may introduce this lesson with a short sketch of the whale. He should remind the children that the whale, although it looks very much like a fish, and, like a fish, spends the whole of its time in the water, is not a fish. It suckles its young, it breathes the air, and it has warm blood ; and is, therefore, quite as much a mammal as a cat or a cow. There are very many different kinds of whales, large and small, and they frequent various parts of the ocean. Some, like the Greenland whale, prefer the Arctic seas ; others revel in the warm seas of the tropics ; a few seem to have but little choice. All mammals have warm blood ; that is, their bodies are warm like our own. Now water is a good conductor of heat, and were it not for some special provision made to prevent, the water would rob the body of so much heat as to cause the death of the animal. Hence it is that all mammals which frequent the water are provided with specially warm coverings. Those which do not live entirely in the water, like the seal and the otter and the white bear, are provided SPECIMEN LESSONS. 229 with thick warm firs. Those which spend their whole lives in the water, like the whale and the porpoise, are otherwise provided for. The skins are naked on the outside, but just underneath there is a thick layer of oily fat. [|The walrus and the seals have a thin layer of oily fat in addition to the fur.J The thickness of this layer varies from five or six to twenty inches, according to the habitat of the animal. In the Greenland or right whale it is very thick, and is called blubber. In the sperm whale it is thinner, and has received the suggestive name of the blanket. Fat is a bad conductor of heat, and the layer of blubber forms a splendid covering. It is from the layer of oily fat that the train-oil and sperm-oil of commerce is extracted. All the cetaceans, viz., whale-like animals, such as the whales, dolphins, and porpoises, are furnished with a layer of oily fat ; but it is only in a very few that it exists in sufficient quantity to make the capture of the animal remunerative. II. The Whale Fishery. The teacher will describe how the whales are captured, and refer to the danger of the pursuit. Two particular kinds of whale are sought after. (1.) The Greenland whale, for its blubber and whalebone. (2.) The sperm whale, for its spei-maceti and sperm-oil. (1.) From the Greenland whale the blubber is stripped ofi' and either boiled down and the oil extracted on board, or packed in barrels and brought home in a half-putrid state. In the latter case, on reaching port the barrels are emptied into enormous wooden vats. Here it is allowed to settle for some hours, after which the decomposing fat is run off into a copper boiler, and the separation of the crude oil is completed by the application of heat and subsequent pressure. The blubber of a Greenland whale of moderate size will 230 NATURAL HISTOEY OBJECT LESSOTSTS. yield from twenty to thirty tons of " train-oil," valued in the English market at about £30 per ton ; and, in addition, there is the whalebone, worth perhaps from £50 to £100 more. (2.) Spermaceti and sperm-oil are obtained from the sperm whale. This whale is distinguised by an enormous develop- ment of the head, which is half as large as the body. It serves as a kind of float to raise the nostrils above the sur- face of the water. The upper part of the great head is made up of great caverns, filled with an oily fluid. [Question as to how the head acts as a float.] When the whale is made fast to the side of the ship a hole is cut in the top of the head and the oil is drawn up, to the amount of three to four hundred gallons, by means of buckets. On cooling, this sepa- rates as a granular yellow solid substance — crude spermaceti, and an oily liquid — crude sperm-oil. By draining, squeezing, and then purifying, the spermaceti appears as a beautiful pearly-white wax. Mixed with some wax, spermaceti has long been used for the making of candles. It is highly prized for its beautiful appearance, and for the purity of the light produced. Except in hot countries, however, sper- maceti candles have been almost entirely superseded by paraffin candles. [Solid paraffin melts at from 110° to 150° Fah., and it softens and becomes pliable at many degrees below its melting point. Hence it is not suitable for hot climates. By more skilful preparation, and by mixture with some other substances, such as vegetable wax,