CORNELL UNIVERSITY LIBRARY 3 1924 089 940 419 DATE DUE ik.£C^^i^^ kwiw ^^mJ^^mtm ^Wm r^^^v^^^T^F »i - GAVLORD PRINTED IN U.S.A The original of this book is in the Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924089940419 In compliance with current copyright law, Cornell University Library produced this replacement volume on paper that meets the ANSI Standard Z39.48-1992 to replace the irreparably deteriorated original. 2001 "N. '/"s < '■a I -^ V ni-';;? m 4tt-(*.j ■>MJ>A-,A>»S^^: , ^' H" s-,/ * ■frKS '^'ft^'^i-'V i-r-^ t^ ^^ (gntncll HniuctBitg Sithrary FROM THE BENNO LOEWY LIBRARY T ' ■> COLLECTED BY BENNO LOEWY 1854-1919 BEQUEATHED TO CORNELL UNIVERSITY eckeL^Msti.; .I'v.atx.OTh. Srst Dominaiit ^'arie^of Man. MieditaiTanese (^) with R)ur Races, WKatkaskm Wlndogermuuc . f^-~ 1 I H}. rciic Circle ift* / — — — ? / Ff.XV Second Dominant "Vftriety of Maii|. Moncols (7) v/Mhf^ur Jlauces: T^ T7uk>chmese , l^Efreojapanese l':Ei/jh Asians, T-JIralians. ^ -.. ieii>oreaji8 3UlinO£' :N^ortli Pacific Ocean Tropic of Caiser_ '-/'. itaraaese LDpavidas ^Americans 3 EafSrs Equ.a fohiilL rMmgareml. SoitlL Pacific Ocean Tagmamans 'YQufJi^^ Hypothetical Sketch _ if the TTonophylEtic origin aauiof Ae extensitinof thelZEacesofMan Jtoaaleniurla over die Eardu THE HISTOEY OF CPtEATION : OR TEE DEVELOPMENT OF THE EARTH AND ITS INHABITANTS BY THE ACTION OF NATURAL CAUSES. A POPULAR EXrOSITION OF THE DOCTRINE OF EVOLUTEOS IN GENERAL, AND OF THAT OF DAEWIH, GOETHE, AND LAMARCK IN I'ARTICULAR. FHOM THE GEMIAN OF BENST HAECKEL, PBOl'ESSOll IN THE UKIVEESITY OF JENA. THE TRANSLATION REVISED BY rUOFESSOR B. EAY LANKESTER, MA., F.E.B., FJiLljOW OF EXETER COLLEGE, OXFORD. IN TWO VOLUMES. VOL. n. NEW YOEK: D. APPLETON AND COMPANY, 549 . The pseudo-feet radiating from the mucous covering surrounding the central capsule. I. Yellow globular cells, scattered between the latter, containing grains of starch. common central point. The skeletons of other Radiolaria again form symmetrical many-chambered structures, as in tlie ease of the Polythalamia. Perhaps no other group of THE RAY-STREAMEPvS. 67 organisms develop in the formation of their skeletons such an amount of various fundamental forms, such geometrical regularity, and such elegant architecture. Most of the forms as yet discovered, I have given in the atlas accompanying my Monograph of the Radiolaria.^ Here I shall only give as an example the picture of one of the simplest forms, the Cyrtidosphcera ecJdnoides of Nice. The skeleton in this case consists only of a simple treUiced ball (s), with short radial spikes (a), which loosely surround the central capsule (c). Out of the mucous covering, enclosing the latter, radiate a great number of delicate little pseudopodia (p), which are partly drawn back underneath the shell, and fused into a lumpy mass of mucus. Between these are scattered a number of yellow cells (I). Most Acyttaria live only at the bottom of the sea, on stones and seaweeds, or creep about in sand and mud by means of their pseudopodia, but most Radiolaria swim on the surface of the sea by means of long pseudopodia extending in all directions. They Uve together there in immense numbers, but are mostly so small that they have been almost com- pletely overlooked, and have only become accurately known during the last fourteen years. Certain Eadiolaria living in communities (Polycyttaria) form gelatinous lumps of some lines in diameter. On the other hand, most of those living isolated (Monocyttaria) are invisible to the naked eye ; but still their petrified sliells are found accumulated in such masses that in many places they form entire mountains ; for example, the Nicobar Islands in the Indian Aixhipelago, and the Island of Barbadoes in the Antilles. As most readers are probably but little acquainted with the eight classes of the Protista just mentioned, I shall 68 THE HISTORY OF CREATION. now add some further general observations on their natural history. The great majority of all Protista live in the sea, some swimming freely on the surface, some creeping at the bottom, and others attached to stones, shells, plants, etc Many species of Protista also live in fresh water, but only a very small number on dry land (for example, Myxomycetes and some Protoplasta). Most of them can be seen only through the microscope, except when millions of individuals are found accumulated. Only a few of them attain a diameter of some lines, or as much as an inch. Wliat they lack in size of body they make up for by producing astonishing numbers of individuals, and they very considerably influence in this way the economy of nature. The imperishable remains of dead Protista, for instance, the flinty shells of the Diatomese and Radiolaria and the calcareous shells of the Acyttaria, often form large rock masses. In regard to their vital phenomena, especially those of nutrition and propagation, some Protista are more allied to plants, others more to animals. Both in their mode of taking food and in the chemical changes of their living sub- stance, they sometimes more resemble the lower animals, at others the lower plants. Free locomotion is possessed by many Protista, while others are without it ; but this does not constitute a characteristic distinction, as we know of undoubted animals which entirely lack free locomotion, and of genuine plants which possess it. All Protista have a soul — that is to say, are "animate " — as well as all animals and all plants. The soul's activity in the Protista manifests tself in their irritability, that is, in the movements and, iother changes which take place in consequence of median. PHYSIOLOGY OF PHOTISTA. 69 ical, electrical, and chemical irritation of their contractile protoplasm. Consciousness and the capability of wiU and thought are probably wanting in all Protista. However, the same qualities are in the same degree also wanting in many of the lower animals, whereas many of the higher animals in these respects are scarcely inferior to the lower races of hiunan beings. In the Protista, as in all other organisms, the activities of the soul are traceable to molecular motions in the protoplasm. The most important physiological characteristic of the kingdom Protista hes in the exclusively non-sexual pro- pagatio7i of all the organisms belonging to it. The higher animals and plants multiply almost exclusively in a sexual manner. The lower animals and plants multiply also, in many cases, in a non-sexual manner, by division, the form- ation of buds, the formation of germs, etc. But sexual propagation almost always exists by the side of it, and often regularly alternates with it in succeeding generations (Meta- genesis, vol. i. p. 20G). AU Protista, on the other hand, pro- pagate themselves exclusively in a non-sexual manner, and in fact, the distinction of the two sexes among them has not been effected — there are neither male nor female Protista. The Protista in regard to their vital phenomena stand midwa.y between animals and plants, that is to say, between their lowest forms ; and the same must be said m regard to the chemical composition of their bodies. One of the most important distinctions between the chemical composition of animal and vegetable bodies consists in the characteristic formation of the skeleton. The skeleton, or the solid scaffold- ing of the body in most genuine plants, consists of a sub- stance called cellulose, devoid of nitrogen, hut secreted by the 70 THE HISTORY OF CREATION. nitrogenous cell-substance, or protoplasm. In most genuine animals, on the other hand, the skeleton generally consists either of nitrogenous combinations (chitin, etc.) or of cal- careous earth. In this respect some Protista are more like plants, others more like animals. In many of them the skeleton is principally or entirely formed of calcareous earth, which is met with both in animal and vegetable bodies. But the active vital substance in all cases is the mucous protoplasm. In regard to the form of the Protista, it is to be remarked that the individuality of their body almost always remains at an extremely low stage of development. Very many Pro- tista remain for life simple plastids or individuals of the first order. Others, indeed, form colonies or republics of plastids by the union of several individuals. But even these higher individuals of the second order, formed by the combination of simple plastids, for the most part remain at a very low stage of development. The members of such communities among the Protista remain very similar one to another, and never, or only in a slight degree, commence a division of labour, and are consequently as little able to render their community fit for higher functions as are, for example, the savages of Australia. The community of the plastids re- mains in most cases very loose, and each single plastid retains in a great measure its own individual independence. A second structural characteristic, which next to their low stage of individuality especially distinguishes the Protista, is the low stage of development of their stereometrical fundamental forms. As I have shown in my theory of fundamental forms (in the fourth book of the General Morphology), a definite geometrical fundamental form can PRO -MORPHOLOGY OF PROTISTA. 7 1 be pointed out in most organisms, both in the general form of the body and in the form of the individual parts. This ideal fundamental form, or type, which is determined by the number, position, combination, and differentiation of the component parts, stands in just the same relation to the real' organic form as the ideal geometrical fundamental form of crystals does to their imperfect real form. In most bodies and parts of the bodies of animals and plants this fundamental form is a pyramid. It is a regular pyramid in the so-called " regular radiate " forms, and an irregular pyramid in the more highly differentiated, so-caUcd " bilaterally symmetri- cal " forms. (Compare the plates in the first volume of my General Moqihology, pp. 55G-558.) Among the Protista this pyramidal type, vi^hich prevails in the animal and vegetable kingdom, is on the whole rare, and instead of it we have either quite irregular (amorphous) or more simple, regular geometrical types; especially frequent are the sphere, the cylinder, the ellipsoid, the spheroid, the double cone, the cone, the regular polygon (tetrahedron, hexhahedron, octahedron, dodecahedron, icosahedron), etc. All the fundamental forms of the pro-morphological system, which are of a low rank in that system, prevail ia the Protista. However, in many Protista there occur also the higher, regular, and bilateral types, fundamental forms which predominate in the animal and vegetable kingdoms. In this respect some of the Protista are frequently more closely allied to animals (as the Acyttaria), others more so to plants (as the Radiolaria). With regard to the palceontological development of the kingdom Protista, we may form various, but necessarily very unsafe, genealogical hypotheses. Perhaps the individual classes of the kingdom are independent tribes, or phyla. ']2 THE HISTORY OF CREATION. which have developed independently of one another and independently of the animal and the vegetable kingdoms. Even if we adopt the monophyletic hypothesis of descent^ and maintain a common origin from a single form of Moneron for all organisms, without exception, which ever have lived and still live upon the earth, even in this case the connection of the neutral Protista on the one hand with the vegetable kingdom, and on the other hand with the animal kingdom, must be considered as very vagTie. We must regard them (compare p. 74) as lower offshoots which have developed directly out of the root of the great double- branched organic pedigree, or perhaps out of the lowest tribe of Protista, which may be supposed to have shot up midway between the two diverging high and vigorous trunks of the animal and vegetable kingdoms. The individual classes of the Protista, whether they are more closely connected at their roots in groups, or only form a loose bunch of root off- sets, must in this case be regarded as having nothing to do either with the diverging groups of organisms belonging to the animal kingdom on the right, or to the vegetable kingdom on the left. They must be supposed to have retained the original simple character of the common primaeval living thing more than have genuine animals and genuine plants. But if we ado]3t the polyphyletic hypothesis of descent, we have to imagine a number of organic tribes, or phyla, which all shoot up by spontaneous generation out of the same ground, by the side of and independent of one another. (Compare p. 75.) In that case numbers of dif- ferent Monera must have arisen by spontaneous generation whose differences would depend only upon slight, to us imperceptible, differences in their chemical composition, and COMMON ORIGm OF PLANTS AND ANIMALS. 'Ji consequently upon differences in their capability of develop- ment. A small number of Monera would then have given origin to the animal kingdom, and, again, a small number would have produced the vegetable kingdom. Between these two groups, however, there would have developed, indepen- dently of them, a largo number of independent tribes, which have remained at a lower stage of organization, and which have neither developed into genuine plants nor into genuine animals. A safe means of deciding between the monophyletic and olyphyletic hypotheses is as yet quite impossible, consider- ing the imperfect state of our phylogenetic knowledge. The different groups of Protista, and those lowest forms of the animal kingdom and of the vegetable kingdom which are scarcely distinguishable from the Protista, show such a close connection with one another and such a confused mixture of characteristics, that at present any systematic division and arrangement of the groups of forms seem more or less artificial and forced. Hence the attempt here offered must be regarded as entirely provisional. But the more deeply we penetrate into the genealogical secrets of this obscure domain of inquirj'-, the more probable appears the idea that the vegetable kingdom and the animal kingdom are each of independent origin, and that midway between these two great pedigrees a number of other independent small o-roups of organisms have arisen by repeated acts of spontaneous generation, which on account of their indiSferent neutral character, and in consequence of their mixture of animal and vegetable properties, may laj"- claim to the designation of independent Protista. Thus, if we assume one entirely independent trunk for 74 THE HISTOET? OF CEEATlON. II. Utgctablc Iftingiom Plantae Flowering Plants Phanerogamia Perna FiliciruB III. 9ttimal ISingtiom Animalia Vertebrate Animals Verteirata Articulated Animals Arthropcda Star-fishes Echinoderma Mosses Muscince AlgcB RIoUascoTis Animala MoUu$ca Lichens Lichenes Fungi Fungi Worms Vermes Animal-trees Zuophijtes I. Hcuttal ^rimtrbal Plants Pvimaijal ffiHatutts primtciial animala Protophyta Protista Protozoa Vegetable Monera Neutral Jlonera Animal Monera attljigani: lIHontta (Pieces of Protoplasm which have originated by Spontaucons Generation) POLYPHYLETIC PEDIGREE. 75 n. Fegctablc SingSom Vegetabilia I. protista Protista ni. Slnimal Animalia Slime-monlds, or Mncons Fnngi Myxomycetes Eay. streamers Rhizopoda, PtimDcbal plants Protopliyta Utgetablt IHoncra Whip- Ewimmers Flagellata Tram. t t Plimmer- balls Catallacta i3tima'bal Animals Protozoa animal fRnncra t t N.B. — The Lines marked with a f indicate extinct tribes of Protista, which hare arisen independently by repeated acts of Spontaneous Generation. "](> THE HISTOKY OF CEEATION. the vegetable kingdom, and a second for the animal king- dom, we may set up a number of independent stems of Protista, each of which has developed, quite independently of other stems and trunks, from a special archigonic form of Monera. In order to make this relation more clear, we may imagine the whole world of organisms as an immense meadow which is partially withered, and upon which two many-branched and mighty trees are standing, likewise partially withered. The two great trees represent the animal and vegetable kingdoms, their fresh and still green branches the living animals and plants ; the dead branches with withered leaves j-epresent the extinct groups. The withered grass of the meadow corresponds to the numerous extinct tribes, and the few stalks, still green, to the still living phyla of the kingdom Protista. But the common soil of the meadow, from which all have sprung up, is primc3val by pnjlopla-aia. CHAPTER XYII. PEDIGREE AND HISTORY OF THE VEGETABLE KINGDOIM. The Natural System of the Vegetable Kingdom. — Division of the Vepre- table Kingdom into S':; Branches and Eighteen Classes. — The Flowerlesg Plants (Cryptogamia). — Sub-kingdom of the Thallus Plants. — The Tangles, or Algae (Primary Algao, Green AlgiB, Brown ■ Algae, Ked Alras.) —The Thread-plants, or Inophytes (Lichens and Fnngi.) — Sub-kingdom of the Prothallus Plants. — The Mosses, or Muscinae (Water.mossos, Liverworts, L«'af.mosscs, Bog-mosses). — The Perns, or Filicina) (Leaf-ferns, Bamboo-ferns, Water-ferns, Seale- ferns). — Sub-kingdom of Flowering Plants (Phanerogamia). — The C-rymnosperms, or Plants with Naked Seeds (Palm-ferns ^= CycadeBe ; Pines = Conif eras.) — The Angiosperms, or Plants with Enclosed Seeds. — "\Ior10cotyla3. — Dicotylas. — Cnp-blossoms (Apetalfe). — Star-blossoms (Diapctala;). — Ecll-blossoms (Gamopetalaj). EvEEY attempt that we make to gain a knowledge of the pedigree of any small or large group of organisms related by blood must, in the first instance, start with the evi- dence afforded by the existing "natural system" of this group. For although the natural system of animals and plants will never become finally settled, but will always represent a merely approximate knowledge of true blood relationship, stiU it will always possess great import- ance as a hypothetical pedigi'ee. It is true, by a " natui-al sj'.stem " most zoologLsts and botanists only endeavour to express in a concise way iihe subjective conceptions which yS THE HISTOKY OF CEEATION. each has formed of the objective " foi^i-relationships " of organisms. These form-relationships, however, as the reader has seen, are in reality the necessary result of true blood relationship. Consequently, every morphologist in promot- ing our knowledge of the natural system, at the same time promotes our knowledge of the pedigree, whether he wishes it or not. The more the natural system deserves its name, and the more firmly it is established upon the concordance of results obtained from the study of comparative anatomy, ontogeny, and palaeontology, the more surely may we con- sider it as the approximate expression of the true pedigree of the organic world. In entering upon the task contemplated in this chaptei*, the genealogy of the vegetable kingdom, we shall have, according to this principle, first to glance at the natural system of the vegetable kingdom as it is at present (with more or less important modifications) adopted by most botanists. According to the system generally in vogue, the whole series of vegetable forms is divided into two main groups. These main divisions, or sub-kingdoms, are the same as were distinguished more than a century ago by Charles LinniBus, the founder of systematic natural history, and which he called Cryptogamia, or secretly-blossoming plants, and Phanerogamia, or openly-flowering plants. The latter, LinnseuB, in his artificial system of plants, divided, accordino- to the different number, formation, and combination of Ca anthers, and also according to the distribution of the sexual organs, into twenty-three different classes, and then added the Cryptogamia to these as the twenty-fourth and last class. The Cryptogamia, the secretly-blossomiiig or llowerless TflE CLASSIFICATION OF PLANTS. 79 plants, which were formerly but little ohserved, have in con- sequence of the careful investigations of recent times been proved to present such a great variety of forms, and such a marked difference in their coarser and finer structure, that we must distinguish no less than fourteen different classes of them ; whereas the number of classes of flowering plants, or Phanerogamia, may be limited to four. However, these eighteen classes of the vegetable kingdom can again be naturally grouped in such a manner that we are able to dis- tinguish in all six main divisions or branches of the vege- ■ table kingdom. Two of these six branches belong to the flowering, and four to the flowerless plants. The table on page 82 shows how the eighteen classes are distributed among the six branches, and how these again fall under the suh-hingdoms of the vegetable kingdom. The one sub-kingdom of the Cryptogamia may now be naturally divided into two divisions, or sub-kingdoms, differ- ing very essentially in their internal structure and in their external form, namely, the ThaUus plants and the ProthaUus plants. The group of Thallus plants comprises the two large branches of Tangles, or AJgse, which live in water, and the Thread-plants, or Inophytes (Lichens and Fungi), which gTOW on land, upon stone,s, bark of trees, upon decaying bodies, etc. The group of ProthaUus plants, on the other hand, comprises the two branches of Mosses and Ferns, containing a great variety of forms. All Thallus plants, or Thallophytes, can be directly recog- nized from the fact that the two morphological fundamental organs of aU other plants, stem and leaves, cannot be dis- tinguished in thoir structure. The complete body of aU Algse and of all Thread-plants is a mass composed of simple 8o THE HISTORY OF CREATION. cells, wliicli is called a lohe, or tJiallus. This thallus is as yet Bot differentiated into axial-organs (stem and root) and leaf-organs. On this account, as well as through many other peculiarities, the Thallophytes contrast strongly with all remaining plants — those comjirised under the two sub- kingdoms of Prothallus plants and ^Flowering plants — and for this reason the two latter sub-kingdoms are frequently classed together under the name of Stemmed 2ila,7ils, or Cori7wphytes. The following table will explain the relation of these three sub-kingdoms to one another according to the two different views : — I. Flowovless Plants. ( Cryptogamia) II. Flowering Plants (^PJianerogamia) A. Thallus Plants {Thallophyta) I B, Prothallus Plants {Profhallophyta) f C. Flowering Plants j (Phanerogamia) j I. Thallus Plants {Tlialluplujta) II. Stemmed Plants {CormophyUx) The stemmed plants, or Cormophytes, in the organization of which the difference of axial-organs (stem and root) and leaf-organs is already developed, form at present, and have, indeed, for a very long period formed, the principal portion of the vegetable woild. However, this was not always the case. In fact, stemmed plants, not only of the flowering group, but even of the prothallus group, did not exist at all during that immeasurably long space of time which forms tlie beginning of the first gi-eat division of the organic history of the earth, under the name of the archilithic, or primordial period. The reader will recollect that durino- this period the Laurcntian, Cambrian, and Silurian systems of strata were deposited, the thickness of which, taken as a whole. THE ALGM, OR TANGLES. 8 1 amounts to about 70,000 feet. Now, as the thickness of all the more recent superincumbent strata, from the Devonian to the deposits of the present time, taken together, amounts to only about 60,000 feet, we were enabled from this fact alone to draw the conclusion — which is probable also for other reasons — that tlie archilithic, or primordial, period was of longer duration than the whole succeeding period down to the present time. During the whole of this immeasur- able space of time, which probably comprises many millions of centuries, vegetable life on our earth seems to have been represented exclusively by the sub-kingdom of Thallus plants, and, moreover, only by the class of marine Thallus plants, that is to say, the Algse. At least all the petrified remains which are positively known to be of the primordial period belong exclusively to this class. As all the animal remains of this immense period also belong exclusively to animals that lived in water, we come to the conclusion that at that time organisms adapted to a life on land did not exist at all. For these reasons the first and most imperfect of the great provinces or branches of the vegetable kingdom, the division of the Algse, or Tangles, must be of special interest to us. But, in addition, there is the interest which this group offers when viewed by itself. In spite of the exceedingly simple composition of their constituent cells, which are but little differentiated, the Algse show an extraordinary variety of different forms. To them belong the simplest and most imperfect of all forms, as well as very highly developed and peculiar forms. The different groups of Algte are dis- tinguished as much by size of body as by the peifcetion and variety of their outer form. At the lowest stage we find 82 THE HISTOllY OF CEBATION. SYSTEMATIC VIEW Of the Six Branches and Eighteen Glasses of the Vegetable Kingdom. Prhiiarii Groyps or Stth-Kiiifjdoins or llie Vef/etablc Aiiigdom. Brandies or Ckides of tlie VegeUihie. Kinr/dojii. Classes of the Vegetable Kingdom. Systematic yame of the CUisses. ffifjalhts i)3Innts ThaUophyta B. ^tatfiallus laiants Prothallophyta inotDcringPlants ] Phanerogamia I. AlgK Tanfrles 11. Thread-plixnts Itiophyta III. Mosses Muscinai IV. Feriis Felicince Plants witK Naked Seeds Gyninosperma VI. Plants with Enclosed Seeds Angiosperma 1. Prima>val al-a3 2. Green algas 3. Brown algce 4. Red algee 5. Licliena 6. Fungi 7. Tangle-mosses 8. Liverworts 9. Frondose- niosEcs 10. Turf-mosses 11. Shaft-ferns 12. Frondose- ferns 13. Aquatic ferns 14. Scale-ferns 15. Palm-ferns 16. Pines 1. Archephyceee (Protophyta) 2. Chlorophyceco (Chloroalgue) 3. Phceophycece (Fucoideaa) 4. RlwdopJiycece (Flcridea;) 5. Lichenes 6. Fungi V. Charohrya, (Characeaj) 8. Thallohrya (Ilepaticse) 9. Phyllohrya, (FrondosEe) 10. Spliagnohrya (Spliagnacete) 11. Calatnarim (Calamophyta) 12. Filices (Pteridcas) 13. Rhizocarpece (Hydropteridea) 14. SelaginecB (Lepidophyta) 15. Cycadoee 16. Coni/ercB 17. Plants with 17. Monocotyloe one seed lobe 18. Plants with 18. Dicotylai two seed lobes PEDIGREE OF THE VEGETABLE KIKGDOM. S3 Qamopetalos (Flowers with cyrolla) Dialypetaloe (Star-shaped flowers) MoTi^chlawydecB (Flowers with calyx) Dicotyledon* (Two seed-lobed plants) Monocotyledon* (One seed-lobed plants) CONIKER^ Cycade* (Pines) (Palm-ferns) G.VETACEjE Angiospermee (Plants with enclosed seeds) Gynmospermae (Plants with naked seeds) Phanerogamx (Flowering plants) Ptcridcce Selaginew (Scaled-ferns) RhizocarpecB (Water-ferns) (Frondose-fems) Calamarim (Shaft-ferns) Frondosos Sphagnacece (Leaf-mosses) (Tarf-mosses) Filicinae (Ferns) Charace^ (Tangle-mosses) Hepatuee (Liverworts) FlorideCB (Bed Algae) Fucoidere (Brown Algse) Muscinae (Mosses) 1 lAchenes CMorophycecu (Lichens) ((ireen Algaa) I Algae (Tangles) Fungi inophyta (Tliread-plants) Protopkyta (Primaeral Plants) Vegetable Monera 84 THE HISTORY OF CKEATION. such species as the mimite Protococeus, several hundred thousands of which occupy a space no larger than a pin's head. At the highest stage we marvel at the gigantic Macrocysts, which attain a length of from 300 to 400 feet, the Jongest of all forms in the vegetable kingdom. It is possible that a large portion of the coal has been formed out of Algae. If not for these reasons, yet the Algas must excite our special attention from the fact that they form the beginning of vegetable life, and contain the original forms of aU other groups of plants, supposing that our monophyletic hypo- thesis of a common origin for aU groups of plants is correct. (Compare p. 83.) Most people living inland can form but a very imperfect idea of this exceedingly interesting branch of the vege- table kingdom, because they know only its proportionately small and simple representatives living in fresh water. The slimy green aquatic filaments and flakes of our pools and ditches and springs, the light green slimy coverings of all kitids of wood which have for any length of time been in contact with water, the yellowish green, frothy, and oozy growths of our village ponds, the green filaments resembling tufts of hair which occur everywhere in fresh water, stag- nant and flowing, are for the most part composed of dif- ferent species of Algae. Only those who have visited the sea-shore, and wondered at &e immense masses of cast-up seaweed, and who, from the rocky coast of the Mediterranean, have seen through the clear blue waters the beautifully-formed and highly-coloured vegetation of Algas at the bottom, know how to estimate the importance of the class of Algse. And yet, even these marine Algje-forests of EaL-()])ean shores, so rich in forn s, give only a faint idea THE CLASSES OF ALG^. 85 of the colossal forests of Sargasso in the Atlantic ocean, those immense banks of Algse, covering a space of about 40,000 square miles — the same which made Columbus, on his voyage of discovery, believe that a continent was near. Similar but far more extensive forests of Algsc grew in the primaaval ocean, probably in dense masses, and what countless genera- tions of these ai-chilithic Algse have died out one after another is attested, among other facts, by the vast thickness of Silurian alum schists in Sweden, the peculiar composition of which proceeds from those masses of submarine Algse. According to the recently expressed opinion of Frederick Mohr, a geologist of Bonn, even the greater part of our coal seams have arisen out of the accumulated dead bodies of the Algas forests of the ocean. Within the branch of the Algae we distinguish four diiferent classes, each of which is again divided into several orders and families. These again contain a large number of different genera and species. We designate these four classes as Primaeval Algae, or Archephycess, Green Algae, or Ghlorophyceaa, Brown Algse, or Pli£eophyce£8, and Red Algse, or Rhodophyceae. The first class of Algse, the PrimcEval Algae (Archephycese), might also be called primmval plants, because they contain the simplest and most imperfect of all plants, and, among them, those most ancient of all vegetable organisms out of which aU other plants have originated. To them therefore belong those most ancient of all vegetable Monera which arose by spontaneous generation in the beginning of the Laurentian period Furtlicr, we have to reckon among them all those vegetable forms of the simplest organization which first developed out of the Monera in the Laurentian period, 86 THE HISTORY OF CREATION. and which possessed the form of a single plastid. At first the entire body of one of these small primary plants consisted only of a most simple cytod (a plastid -without kernel), and afterwards attained the higher form of a simple cell, by the separation of a kernel in the plasma. (Compare above, vol. i. p. 345.) Even at the present day there exist various most simple forms of Algae which have devi- ated but little from the original primary plants. Among them are the Alg so rich in forms, with its numerous and important species, sprvices, pines, firs, larches, etc. — still play a very important part in the most different parts of the earth, and almost of themselves consti- tute extensive forests. Yet this development of pines seems but weak in comparison with the predominance which the class had attained over other plants during the early ANQIOSPERMS. 1 1 I secondary period, that of the Trias. At that time mighty coniferous trees — with but proportionately few genera and species, but standing together in immense masses of indivi- duals — formed the principal part of the mesolithic forests. This fact justifies us ia calling the secondary period the " era of the pine forests," although the remains of Cycadeffi predominate over those of coniferous trees in the Jura period.* From the pine forests of the mesolithic, or secondary period, we pass on into the leafy forests of the cffinolithic, or tertiary period, and we arrive thus at the consideration of the sixth and last class of the vegetable kingdom, that of the Metaspermce, Angiospermce, or plants ivith enclosed seeds. The first certain and undoubted fossils of plants with enclosed seeds are found in the strata of the chalk system, and indeed Ave here find, side by side, remains of the two classes into which the main class of Angiosperms is generally divided, namely, the one seed-lohed plants, or nnonocotylcB, and the two seed-lohed plants, or dicotyloi. However, the whole gToup probably originated at an earlier period during the Trias. For we know of a number of doubtful and not accurately definable fossil remains of plants from the Oolitic and Trias (sic) periods, which some botanists consider to be Monocotylse, whilst others consider them as Gymnosperms. In regard to the two classes of * The primary stock of the Coniferse divided into two branches at an early period, into the Araticarice on the one hand, and the Taxaceas, or yew-trees, on the other. The majority of recent Coniferse are derived from the former, Ont of the latter the third class of the Gymnosperms — the Meninges, or Gnetaceoe — were developed. This small bnt very interesting class contains only three different genera — Gnetum, Welwitschia, and Kphodra ; it is, however, of great importance, as it forms the transition groap from the Coniferaa to the Angiosiierms, and more especially to the Dicotyledons. I r 2 THE HISTORY OF CREATION. plants with enclosed seeds, the Monocotylse and Dicotylse, it is exceedingly probable that the Dicotyledons developed out of the GnetacetE, but that the Monocotyledons developed later out of a branch of the dicotyledons. The class of one seed-lobed plants (Monocotylte, or Monocotyledons, also called Endogenas) comprises those flowering plants whose seeds possess but one germ leaf or seed lobe (cotyledon). Each whorl of its flower contains in most cases tho^ee leaves, and it is very probable that the mother plants of all Monocotyledons possessed a regular triple blossom. The leaves are mostly simple, and traversed by sifuple, straight bunches of vessels or " nerves." To this class belong the extensive families of the rushes, gi-asses, lilies, irids, and orchids, further a number of indigenous aquatic plants, the water-onions, sea grasses, etc., and finally the splendid and higlily developed families of the Aroidese and Pandanea;, the bananas and palms. On the whole, the class of Monocotyledons — in spite of the great variety of forms which it developed, both in the tertiary and the present period — is much more simply organized than the class of the Dicotyledons, and its history of development also ofl"ers much less of interest. As their fossil remains are for the most part difiicult to recognize, it still remains at present an open question in vi'hich of the three great secondary periods— the Trias, Jara, or chalk period — the Monocotyledons originated. At all events they existed in the chalk period as surely as did the Dicotyledons. The second class of plants with enclosed seeds, the tiuo seed-lohed (Dicotylas, or Dicotyledons, also called Exogenas) presents much greater historical and anatomical interest in Eaeckel- History of Oeatiorv. jyiain Divisions of the Tlowerless Plants , Cryptogamae TtallTLsplants, ThalloplrTta. Mosses, Muscinae. Terns, Pilicinae . TL.V. Plover Plants, Phanerogamae. ITaked seeded. Cover- seeded, .Angiospermae. Total 100. Single-stemmed or MONOPHYLETIC PEDIGREE of tlie VEGETABLE KINGDOM tasedanPalaeoiitQlogy. THE FLOWERING PLANTS. II3 the development of its subordinate groups. The flowering plants of this class generally possess, as their name indicates, two seed lobes or germ leaves (cotyledons). The number of leaves composing its blossom is generally not three, as in most Monocotyledons, but four, five, or a multiple of those numbers. Their leaves, moreover, are generally raore highly differentiated and more composite than those of the Mono- cotyledons; they are traversed by crooked, branching bunches of vessels or " veins." To this class belong most of the leafed trees, and as they predominate in the tertiary period as well as, at present, over the Gymnosperms and Ferns, we may call the cjenolithic period that of leafed forests. Although the majority of Dicotyledons belong to the most highly developed and most perfect plants, still the lowest division of them is directly allied to the Gymnosperms, and particularly to the Gnetacese. In the lower Dicotyledons, as in the case of the Monocotyledons, calyx and corolla are as yet not differentiated. Hence they are called Apetalous (Monochlamydea?, or Apetate). This sub-class must there- fore doubtless be looked upon as the original group of the Angiosperms, and existed probably even during the Trias and Jura periods. Among them are most of the leafed trees bearing catkins — ^birches and alders, willows and poplars, beeches and oaks; further, the plants of the nettle kind — nettles, hemp, and hops, figs, mulberries, and elms ; finally, plants like the spurges, laurels, and amarantL It was not until the chalk period that the second and more perfect class of the Dicotyledons appeared, namely, the group with corollas (Dichlamydeae, or Corolliflorse). These arose out of the Apetalte from the simple cover of the 23 114 THE H1ST0E.Y OF CREATION. blossoms of the latter becoming differentiated into caljrs and corolla. The sub-class of the CoroUiflorje is again divided into two large main divisions or legions, each of which contains a large number of different orders, families, genera, and species. The first legion bears the name of star-flowers, or Diapetalse, the second that of the beU-flowers, or Gamopetalse. The lower and less perfect of the two legions of the OoroUiflorse are the star-flowers (also called Diapetalse or Dialypetalae). To them^ belong the extensive families of the TJmbeUifera3, or umbrella-worts (wild carrot, etc.), the Cruci- feraj, or cruciform blossoms (cabbage, etc.) ; further, the Ranuneulaceoe (buttercups) and Crassulaceas, the MaUows and Geraniums, and, besides many others, the large group of Roses (which comprise, besides roses, most of our fruit trees), and the Pea-blossoms (containing, among others, beans, clover, genista, acacia, and mimosa). In all these Diapetalse the blossom-leaves remain separate, and never grow together, as is the case in the Gamopetalge. These latter developed first in the tertiary period out of the Diapetalse, whereas the Diapetalse appeared in the chalk period together with the Apetalse. The highest and most perfect group of the vegetable kingdom is formed by the second division of the OoroUiflorse, namely, the legion of bell-flowers (Gamopetalse, also called Monopetalse or Sympetalffi). In this group the blossom- leaves, which in other plants generally remain separate, grow regularly together into a more or less bell-Uke, funnel- shaped, or tubular flower. To them belong, among others, the BeU-flowers and Convolvulus, Primroses and Heaths, Gentian and Honeysuckle, further the family of the Olives (olive trees, privet, elder, and ash), and finally, besides many THE DESCENT THEORY CONFIRMED. II5 other families, the extensive division of the Lip-blossoms (Labiatse) and the Composites. In these last the differen- tiation and perfection of the Phanerogamic blossoms attain their highest stage of development, and we must therefore place them at the head of the vegetable kingdom, as the most perfect of aU plants. In accordance with this, the legion of the Gamopetalse appear ia the organic history of the earth later than all the main groups of the vegetable kingdom — in fact, not until the cjenolithic or tertiary epoch. In the earliest tertiary period the legion is still very rare, but it gradually increases in the mid-tertiary, and attains its fuU development only in. the latest tertiary and the qua- ternary period. Now if, having reached our own time, we look back upon the tuhole history of the development of the vegetable Idngdom, we cannot but perceive in it a grand confirmation of the Theory of Descent. The two great principles of organic development which have been pointed out as the necessary results of natural selection in the Struggle for Life, namely, the laws of differentiation and ^perfecting, manifest them- selves everywhere in the development of the larger and smaller groups of the natural system of plants. In each laro-er or smaller period of the organic history of the earth, the vegetable kingdom Increases both in variety and perfec- tion, as a glance at Plate IV. will clearly show. During the whole of the long primordial period there existed only the lowest and most imperfect group, that of the Algse. To these are added, in the primary period, the higher and more perfect Cryptogamia, especially the main-class of Ferns. During the coal period the Phanerogamia begin to develop out of the latter; at first, however, they are represented only Il6 THE HISTORY OF CREATION, by the lower main-class, that of Gymnosperms. It was not until the secondary period that the higher main-class, that of Angiospcrms, arose out of them. Of these also there existed at fh-st only the lower groups without distinct corollas, the Monocotyledons and the Apetalee. It was not until the chalk period that the higher Corolliflorse developed out of the latter. But even this most highly developed group is represented, in the chalk period, only by the lower stage of Star-flowers, or Diapetalse, and only at quite a late date, in the tertiary period, did the more highly developed Bell- blossoms, Gamopetalse, arise out of them, which at the same time are the most perfect of aU flowering plants. Thus, in each succeeding later division of the organic history of the earth the vegetable kingdom gradually rose to a higher degree of perfection and variety. CHAPTER XVIir. PEDIGREE AJSD HISTORY OF THE ANIMAL KINGDOM. I. Animal-Plants and Wobms. The Natural System of the Animal Kingdom.— Linn sens and Lamarck's Systems.— The Pour Types of Bar and Cuvier.— Their Increase to Seven Types.— Genealogical Importance of the Seven Types as Independent Tribes of the Animal Kingdom. — Derivation of Zoophytes and Worms from Primajval Animals. — Monophyletio and Polyphyletic Hypothesis of the Descent of the Animal Kingdom. — Common Origin of the Four Higher Animal Tribes ont of the Worm Tribe. — Division of the Seven Animal Tribes into Sixteen Main Classes, and Thirty-eight Classes. — Pri. mseval Animals (Monera, Amcebse, Synamoebas), Gregarinea, Infusoria, Plauseades, and Gaatrseades (Plannia and Gastrula). — Tribeof Zoophytes. — Spongise (Mucous Sponges, Fibrous Sponges, Calcarcoa? Sponges). — Sea Nettles, or Aoalephae Corals, Hood-jelUes, Comb-jeilies). — Tribe of Worms. The natural system of organisms which we must employ in the animal as well as in the vegetable kingdom, as a guide in our genealogical investigations, is in both cases of but recent origin, and essentially determined by the progress of comparative anatomy and ontogeny (the history of individual development) during the present century. Almost all the attempts at classification made in the last century followed the path of the artificial system, which was first established in a consistent manner by Charles I 1 8 THE HISTOEY Of CKEATION. Linnseus. The artificial system differs essentially from the natural one, in the fact that it does not make the whole organization and the internal structure (depending upon the blood relationshijj) the basis of classification, but only employs individual, and for the most part external, charac- teristics, ■which readily strike the eye. Thus Linnffius dis- tinguished his twenty -four classes of the vegetable kingdom principally by the number, formation, and combination of the stamens. In like manner he distinguished sis classes in the animal kingdom principally by the nature of the heart and blood. These six classes were : (1) Mammals ; (2) Birds ; (3) Amphibious Animals ; (4) Fishes ; (5) Insects ; and (6) Worms. But these six animal classes of Linnseus are by no means of equal value, and it was an important advance when, at the end of the last century, Lamarck comprised the first four classes as vertebrate animals (Vertebrata), and put them in contrast with the remaining animals (the insects and worms of Linnasus), of which he made a second main division —the invertebrate animals (In vertebrata). In reality Lamarck thus agreed with Aristotle, the father of Natural History, who had distinguished these two main groups, and called the former blood-hearing animals, the latter bloodless animals. The next important progress towards a natural system of the animal kingdom was made some decades later by two most illustrious zoologists, Carl Ernst Bar and George Cuvier. As has already been remarked, they established, almost simultaneously and independently of one another, the pro- position that it was necessary to distinguish several com- pletely distinct main groups in the animal kingdom, each of TYPES IN THE ANIMAL KINGDOM. II 9 which possessed an entirely peculiar type or structure (com- pare above, vol. i. p. 53). In each of these main divisions there is a tree-shaped and branching gradation from most simple and imperfect forms to those which are exceedingly composite and highly developed. The degree of development within each type is quite independent of the peculiar plan of structure, which forms the basis of the type and gives it a special characteristic. The " type " is determined by the peculiar relations in position of the most important parts of the body, and the manner in which the organs are connected. The degree of development, however, is dependent upon the greater or less division of labour among organs, and on the differentiation of the plastids and organs. This extremely important and fruitful idea was established by Bar, who relied more distinctly and thoroughly upon the history of individual development than did Cuvier. Cuvier based his argument upon the results of comparative anatomy. But neither of them recognized the true cause of the re- markable relationships pointed out by them, which is first revealed to us by the Theory of Descent. It shows us that the common type or plan of structure is determined by iw- heritance, and the degree of development or diflferentiation by adaptation. (Gen. Morph. ii. 10). Both Bar and Cuvier distinguished four different types in the animal kingdom, and divided it accordingly into four gi-eat main divisions (branches or circles). The fu'st of these is formed by the vertebrate animals (Vertebrata), and comprises Linnseus' first four classes — mammals, birds, amphibious animals, and fishes. The second type is formed by the articulated animals (Articulata), containing Linnseus' insects, consequently the six-legged insects, and also the 120 THE HISTORY OF CEEATION. myriopods, spiders, and Crustacea, but besides these, a large number of the worms, especially the ringed worms. The third main division comprises the molluscous animals (Mollusca) — slugs, snails, mussels, and some kindred groups. Finally, the fourth and last circle of the animal kingdom comprises the various radiated animals (Radiata), which at first sight differ from the three preceding typos by their radiated, flower-like form of body. For while the bodies of moUuscs, articulated animals, and vertebrated animals consist of two symmetrical lateral halves — of two counterparts or antimera, of which the one is the mirror of the other — the bodies of the so-called radiated animals are composed of more than two, generally of four, five, or six counterparts grouped round a common central axis, as in the case of a flower. However striking this difierence may seem at first, it is, in reahty, a very subordinate one, and the radial form has by no means the same importance in all " radiated animals." The establishment of these natural main groups or types of the animal kingdom by Bar and Cuvier was the greatest advance in the classification of animals since the time of Linnajus. The three groups of vertebrated animals, articu- lated animals, and moUuscs are so much in accordance with nature that they are retained, even at the present day, little altered in extent. But a more accurate knowledge soon showed the utterly unnatural character of the group of the radiated animals. Leuckart, in 1848, first pointed out that two perfectly distinct types were confounded under the name, namely, the Star-fishes (Echinoderma) — the sea-stars, lily encrinites, sea-urchins, and sea-cucumbers ; and, on the other hand, the Animal-plants, or Zoophytes (Coelenterata, THE SEVEN MODERN TYPES. 121 or Zoopliyta) — the sponges, corals, liood-jelHes, and comb- jellies. At the same time, Siebold united the Infusoria with the Rhizopoda, under the name of Protozoa (lowest animals), into a special main division of the animal kingdom. By this the number of animal types was increased to six. It was finally increased to seven by the fact that modern zoologists separated the main division of the articulated animals into two groups : (a) those possessing articulated feet (Arthropoda), corresponding to Linnasus' Insects, namely, the Flies (with six legs), Myriopods, Spiders, and Crustacea ; and (h) the footless Worms (Vermes), or those possessing non-articulated feet. These latter comprise only the real or genuine Worms (ring-worms, round worms, planarian w^ornis, etc.), and therefore in no way correspond with the Worms of Linnseus, who had included the molluscs, the radiates, and many other lower animals under this name. Thus, according to the views of modern zoologists, which are given in all recent manuals and treatises on zoology, the animal kingdom is composed of seven completely distinct main divisions or types, each of which is distinguished by a characteristic plan of structure peculiar to it, and perfectly distinct from every one of the others. In the natural system of the animal kingdom — ^which I shall now proceed to explain as its probable pedigree — I shall on the whole agree with this usual division, but not without some modifications, which I consider very important in connection with genealogy, and which are rendered absolutely necessary in consequence of our view as to the history of the development of animals. We evidently obtain the greatest amount of information concerning the pedigree of the animal kingdom (as well as concerning that of the vegetable kingdom) from comparative 122 THE HISTORY OF CREATION, anatomy and ontogeny. Besides these, palasontology also throws much valuable light upon the historical succession of many of the groups. From numerous facts in comparative anatomy, we may, in the first place, infer the common origin of all tlwse animals which belong to one of the seven " types." For in spite of aU the variety in the external form developed within each of these types, the essential relative position of the parts of the body which determines the type, is so constant, and agrees so completely in aU the members of every type, that on account of their relations of form alone we are obliged to unite them, in the natural system, into a single main group. But we must certainly conclude, moreover, that this conjunction also has its expression in the pedigree of the animal kingdom. For the true cause of the intimate agreement in structure can only be the actual blood relationship. Hence we may, without further discussion, lay down the important proposition that all animals belonging to one and the same circle or type must be descended from one and the same original primary form. In other words, the idea of the circle or type, as it is employed in zoology since Bar and Cuvier's time to designate the few principal main groups or " sub-kingdoms " of the animal kingdoms, coincides with the idea of " tribe " or " phylum," as employed by the Theory of Descent. If, then, we can trace all the varieties of animal forms to these seven fundamental forms, the following question next presents itself to us as a second phylogenetic problem — Wliere do these seven animal tribes come from ? Are they seven original primary forms of an entu-ely independent origin, or are they also distantly related by blood to one another ? TJaueckel-Histary ofCreatUm,. FL.Vl. m- INFERENCES FROM ONTOGENy. 1 23 At first we might be inclined to answer tliis question in a polyphyletic sense, by saying that we must assume, for each of the seven great animal tribes, at least one independent primary form completely distinct from the others. On further considering this difficult problem, we arrive in the end at the notion of a monophyletic origin of the aidmal kingdom, viz., that these seven primary forms are connected at their lowest roots, and that they are derived from a single, common primaeval form. In the animal as well as in the vegetable kingdom, when closely and accurately considered, tJis m,onophyletic hypothesis of descent is found to be 7)%ore satisfactory than the polyphyletic hypothesis. It is comparative ontogeny (embryology) which first and foremost leads to the assumption of the monophyletic origin of the whole animal kingdom (the Protista excepted of course). The zoologist who has thoughtfully compared the history of the individual development of various animals, and has understood the importance of the biogenetic principle (p. 33), cannot but be convinced that a common root must be assumed for the seven different animal tribes, and that all animals, including man, are derived from a single, common primary form. The result of the consideration of the facts of embryology, or ontogeny, is the following genealogical or phylogenetic hypothesis, which I have put forward and explained in detail in my " Philosophy of Calcareous Sponges" (Monograph of the Calcareous Sponges, vol. i. pp. 464, 465, etc., — "the Theory of the Layers of the Embryo, and the Pedigree of Animals.") The first stage of organic life in the Animal kingdom (as in the Vegetable and Protista kingdoms) was formed by per- fectly simple Monera, originating by spontaneous generation. 124 ^^^ HISTORY OF CEEATION. The former existence of this simplest animal form is, even at present, attested by the fact that the egg-cell of many animals loses its kernel directly after becoming fructified, and thus relapses to the lower stage of development of a cytod without a kernel, like a Moneron. This remarkable occurrence I have interpreted, according to the law of latent inheritance (vol. i. p. 205), as a phylogenetic 7'elapse of the cellular form into the original form of a cytod. The Monerula, as we may caU this egg-cytod without a kernel, repeats then, according to the biogenetic principle (vol ii. p. 33), the most ancient of all animal forms, the common pri- mary form of the animal kingdom, namely, the Moneron, The second ontogenetic process consists in a new kernel being formed in the Monerula, or egg-cytod, which thus returns again to the value of a true egg-cell. According to this, we must look upon the simple animal cell, containing a kernel, or the single-celled primajval animal — which may still be seen in a living state in the Aonaibce of the present day — as the second step in the series of phylogenetic forms of the animal kingdom. Like the still living simple Amoebss, and like the naked egg-cells of many lower animals (for example, of Sponges and Medusse, etc.), which cannot be distinguished from them, the remote phyletic primary Amoebse also were perfectly simple naked-cells, which moved about in the Laurentian primseval ocean, creeping by means of the ever-changing processes of their body-substance, and nourishing and propagating themselves in the same way as the AmoehaB of the present day. (Com- pare vol. i. p. 188, and vol. ii. p. 54) The existence of this Amoeba-like, single-celled primary form of the whole animal kingdom is unmistakably indicated by the exceedingly im- THE EARLIEST ANIMALS.- 125 portant fact that the egg of all animals, from those of sponges and worms up to those of the ant and man, is a simple cell Thirdly, from the " single-cell " state arose the simplest multicellular state, namely, a heap or a small community of simple, equiformal, and equivalent cells. Even at the present day, in the ontogenetic development of every animal egg- cell, there first arises a globular heap of equiformal naked cells, by the repeated self-division of the primary cell. (Com- pare vol. i. p. 190 and the Frontispiece, Fig. 3.) We called this accumulation of cells the Tnulherry state (Morula), because it resembles a mulbeiTy or blackberry. This Morula- body occurs in the same simple foim in all the different tribes of animals, and on account of this most important circumstance we may infer — according to the biogenetic principle — that the Tnost ancient, many-celled, primary form of the anim,al kingdom resembled a Morula like this, and was in fact a simple heap of Amoeba-like primsBval cells, one similar to the other. We shall caU this most ancient community of Amoebae — this most simple accumulation of animal cells — which is recapitulated in individual develop- ment by the Morula — the Synamoeha. Out of the Synamcebse, in the early Laurentian period, there afterwards developed a fourth primary form of the animal kingdom, which we shall call the ciliated germ (PlauEea). This arose out of the Synamoeba by the outer cells on the surface of the cellular community beginning to extend vibrating fringes called cilia, and becoming " cUiated cells," and thus differentiating from the inner and unchanged cells. The Synamoebce consisted of comi^letely equi- formed and naked cells, and crept about slowly, at the bottom of the Laurentian primaeval ocean, by means 126 THE HISTORY OF CEEATIOK. of movements like those of an Amoeba. The Plansea, on the other hand, consisted of two kinds of different cells — inner ones like the AmoebEe, and external " ciliated cells." By the vibrating movements of the cilia the entire multicellular body acquired a more rapid and stronger motion, and passed over from the creeping to the swim- ming mode of locomotion. In exactly the same manner the Morula, in the ontogenesis of lower animals, still changes into a ciHated form of larva, which has been known, since the year 1847, under the name of Planula. This Planula is sometimes a globular, sometim^es an oval body, which swims about in the water by means of a vibrating movement ; the fringed (ciliated) and smaller cells of the surface differ from the larger inner cells, which are unfringed. (Fig. 4 of the Frontispiece.) Out of this Planula, or fringed larva, there then develops, in animals of all tribes, an exceedingly important and interesting animal form, which, in my Monograph of the Calcareous Sponges, I have named Gastrula (that is, larva with a stomach or intestine). (Frontispiece, Fig. 5, 6). This Gastrula externally resembles the Planula, but differs es- sentially from it in the fact that it encloses a cavity which opens to the outside by a mouth. The cavity is the " pi^i- mary intestine," or "primary stomach," the progaster, the first beginning of the alimentary canal ; its opening is the " prirnaTy mouth" (prostoma). The wall of the progaster consists of two layers of cells ; an outer layer of smaller ciliated ceUs (outer skin, or ectoderm), and of an inner layer of larger non-ciliated cells (inner skin, or entoderm). This exceedingly important larval form, the " Gastrula," makes its appearance in the ontogenesis of all tribes of PARALLELISM OF OKTOGENY AND PHYLOGENY. 12/ Definition of fhe forms of the five first stages of the development of the animal body. First Stage of Develop, merit. A simple cytod (a plastid -without a ker- nel.) Second Stage of Develop- ment. A simple cell (a plastid containing a kernel.) Third Stage of Develop- ment. A community (an aggregation of identi- cal simple cells). Fourth Stage of Develop, ment. A solid or bladder- shaped, globular, or oval body, co7n2'yosed of two hinds of different cells: externally ciliated, in. ternally non - ciliated cells. Fifth Stage of Develop, ment. A globular or oval body with simple inies. tinal cavity and mouth, opening. Body wall com. posed of two layers; an externally ciliated ecto- derm (dermal layer), an internally non - ciliated entoderm (gas tral layer), Ontogenesis. The five first stages of the individual de. velopment. 1. XEonernla. Animal egg without a kernel (when the egg- kernel has disappeared, after being fructified). 2. Ovulum. Animal egg with ker. nel (a simple egg-cell) . 3. Morula. (Mulberry form.) Globular heap of ho- mogeneous *' cleavage spheres." I 4. Plannla. (Ciliated larva.) Many - celled larva without mouth, com- posed of different cells. 5. Gastrula. (Larva with tnouth.) Many-celled "n^ith in- testines and month; in- testinal wall with two layers. Phylogenesis. The five first stages of the phyletic or his- torical development. Koneron. Most ancient animal Monera, originating by spontaneous generation. 2. AmcEba. Animal Amoebis, Synamoeba. An aggregation of Amcebae. 4. Plansea. Mnny-celled prim- aeval animal without mouth, composed of two kinds of diiferent cells. 5. Gastraea. Many -celled prim- aeval animal with intes- tine and mouth ; intes- tinal wall with two layers. (PHmary form of zoophytes and worms.) 128 THE HISTOEY OF CREATION. animals — In Sponges, Medusse, Corals, Worms, Sea-squirts Radiated animals. Molluscs, and even in the lowest Ver- tebrata (Amphioxus : compare p. 200, Plate XII., Fig. B 4! ; see also in the same place the Ascidian, Fig. A 4). From the ontogenetic occurrence of the Gastrula in the most different animal classes, from Zoophytes up to Ver- tebrata, we may, according to the biogenetic principle, safely draw the conclusion that during the Laurentian period there existed a common primary form of the six higher anima, tribes, which in all essential points was formed like the Gastrula, and which we shall call the Gastrsea. This Gastrsea possessed a perfectly simple globular or oval body, which enclosed a simple cavity of like form, namely, the progaster ; at one of the poles of the longitudinal axis the primary intestine opened by a mouth which served for the reception of nutrition The body wall (which was also the intestinal wall) consisted of two layers of cells, the unfringed entoderm, or intestinal layer, and the fringed ectoderm, or skin-layer ; by the motion of the cilia or fringes of the latter the Gastrasa swam about freely in the Laurentian ocean. Even in those higher animals, in the ontogenesis of which the original Gastrula form has disappeared, according to the laws of abbreviated inheritance (vol. i. p. 212), the composition of the Gastrsea body has been transmitted to the phase of development which directly arises out of the Morula. This phase is an oval or round disc consisting of two cell- layers or membranea : the outer cell-layer, the animal or dermal layer (ectoblast), corresponds to the ectoderm of the Gastrffia ; out of it develops the external, loose skin (epidermis), with its glands and appendages, as well as the central nervous system. The inner cell-layer, the THE GASTR^ADA. 1 29 vegetative or intestinal layer (hypoblast), is originally the entoderm of the Gastrsea; out of it develops the inner membrane (epithelium) of the intestinal canal and its glands. (Compare my Monograph of the Calcareous Sponges, voL i. p. 466, etc.) By ontogeny -we have already gained five primordial stages of development of the animal kingdom : (1) the Moneron ; (2) the Amceba ; (3) the Synamoeba ; (4) the Plansea ; and (5) the Gastrsea. The former existence of those five oldest primary forms, which succeeded one another, and which must have lived in the Laurentian period, follows as a consequence of the biogenetic principle ; that is to s&j, from the parallelism and the mechanico-causal connection of ontogenesis and phylogenesis. (Compare vol. i. p. 309.) In our genealogical system of the animal kingdom we may class all these animal forms, long since extinct, and, which on account of the soft nature of their bodies could leave no fossd remains, among the tribe of Primaeval animals (Protozoa), which also comprises the stiU living Infusoria and Gregarinse. The phyletic development of the six higher animal tribes, which are all derived from the Gastrsea, deviated at this point in two directions. In other words, the Gastrceads (as we may call the group of forms characterized by the Gastrsea-tj^e of structure), divided into two divergent lines or branches; the one branch of Gastrseads gave up free locomotion, adhered to the bottom of the sea, and thus, by adopting an adhesive mode of life, gave rise to the Pro- tascus, the common primary form of the Animal-planis (Zoophyta). The other branch of the Gastracads retained free locomotion, did not become adlierent and later on 130 THE mSTOKY OF CREATION. developed into the Prothelmis, the common primary form of Worms (Vermes). (Compare p. 133.) This latter tribe (as limited by modern zoology) is of the greatest interest in the study of genealogy. For among Worms, as we shall see later, there are, besides very nume- rous peculiar families, and besides many independent classes, also very remarkable forms, which may be con- sidered as forms of direct transition to the four higher animal tribes. Both comparative anatomy and the on- togeny of these worms enable us to recognize in them the nearest blood relations of those extinct animal forms which were the original primary forms of the four higher animal tribes. Hence these latter, the Molluscs, Star-fishes, Articulated animals, and Vertebrate animals, do not stand in any close blood relationship to one another, but have originated independently in four different places out of the tribe of Worms. In this way comparative anatomy and phylogeny lead us to the raonophyletio 'pedigree of the animal kingdom, the outlines of which are given on p. 133. According to it the seven phyla, or tribes, of the animal kingdom are of different value in regard to genealogy. The original primary group of the whole animal kingdom is formed by the Primsevai animals (Protozoa), including the Infusoria and Gastrseads. Out of these latter arose the two tribes of Animal-plants (Zoophyta) and Worms as diverging branches. Out of four different groups of the Worm tribe, the four higher tribes of the animal kingdom were developed — the Star-fishes (Echinoderma) and Insects (Arthropoda) on the one hand, and the Molluscs (Mollusca) and Vertebrated animals (V'ertebrafa) on the other. THE CLASSES OF ANIMALS. 131 Having thus sketched out the monophyletic pedigree of the animal kingdom in its most important features, we must now turn to a closer examination of the historical course of development which the seven tribes of the animal kingdom, and the classes distinguished in them, have passed through (p. 132). There is a much larger number of classes in the animal than in the vegetable kingdom, owing to the simple reason that the animal body, in consequence of its more varied and perfect vital activity, could differentiate and develope in very many more different directions than could the vegetable body. Thus, while we were able to divide the whole vegetable kingdom into six main classes and nineteen classes, we have to distinguish, at least, sixteen main classes and thirty-eight classes in the animal kingdom. These are distributed among the seven different tribe.s of the animal kingdom in the way shown in the Systematic Survey on pages 132 and 133. The group of PrimcBval animals (Protozoa) within the compass which we here assign to this tribe, comprises the most ancient and the simplest primary forms of the animal kingdom; for example, the five oldest phyletic stages of development previously mentioned, and besides these the Infusoria and Gregarina;, as well as aU those imperfect animal forms, for which, on account of their simple and in- different organization, no place can be found in any of the other six animal tribes. Most zoologists, in addition to these, include among the Protozoa a larger or smaller portion of those lowest organisms, which we mentioned in our neutral kingdom of Protista (in Chapter XVI.). But these Protista, especially the large division of the Rhizopoda, which are so rich in forms, cannot be considered as real animals for 132 THE HISTOE.Y OF CREATION. SYSTEMATIC SUEYEY Of iliG 16 Main Classes and 38 Classes of tJie Animal Kingdom. Ti-ibes or Phyla of the. Animal Kw{/dom. Main Classes, Branches or Clades of the Animal Kingdom. oj' the Animal Kingdom. Si/stematic Naine of the Classes. A. 1 ^timiifaal Snimala I. Esrgr-animals dvulurki 1. Archaic animals 2. Gregarines 3. Infusoria 1. Archezoa 2. Gregarinffi 3. Infusoria Protozoa II. Mulberry animaJs r 4. Plaiiseads Blastularia \ 5. Gastraads 4. Planaiadas 5. Gastrseadas B. , animal plants Zoophyta III. Spongea / 6. Sponges SnonauE *■ ,„„.», f 7. Corals IV. SGa-nettles . e. Hood-jelliea Acalephce | 9. Comb-jeUies 6 Porifcra 7. Coralla 8. Ilydromedusas 9. Ctenophora " 1 JUHnrms ^ Vermes j V. Bloodless worms {10. Planary worms ,11. Roundworms VI. Blood-bearing 12. Moss-polypa worms 13. Sac-worms .^ Cctlumati J 11. Proboecideana 15. Star-worms le. WTieel auimal- V I cules 17. Eing-wormB 10. Platyhelmiuthes 11. Nemathelminthcs 13. Bryozna 13. Tunicata 14. Rhynchoco3la 15. Gephyrea 16. Eotatoria 17. Auuelida D. fHolhiscs . Mollusca VII. Headless shell- j jg j,„mp.sbell3 fish i i9_ Mussels Acepliala VIII. Heart-bearing ( 20. .^Inailg l^ EacepMla | 21. CuUlcs 18. Spirobranchia 19. Lamellibranchia 21. Cnchlidos 21. Ceplialopoda E. Slar=flsljc3 - Echinoderma IX. T!iii»ed-arms Colobrachia X. Armless Lipobrachla 22. Sea-stars [ 23. Lily -stars ( 24. Sea-urchins 1 2.1. Sea-cucumbera 22. Asterida 2.3. Crinoida 24. Echinida 25. Holothuriaj F. grttcuIattJJ animals Arthropoda XI. Gill-breathers Caridcs XII. Tube-breathers 2\a£heata { 2G. Crab-fish 27. Spiders 2S. Centipcdca 2y. llies 20. Crustacea 27. Arachnida 28. Jlyriopoda 29. Insocta ' / XIII. Skull-less Acranla { 30. Lanceleta "0. Leptocardia G. Ucrtchtate animals VerteTirata i^ XIV. Sing-le-noa- triled ii(morTKi.na XV. Amnion -less Anamnia \ 31. Lampreys / 32. Fishes 33. JIud-fish .34, Sea-dray;on3 . 35. Amphibians 31. Cyclostoma 32. Pisces 33. Dipneusta 34. Halisauiia 35. Amphibia XVI. Amnion- 1 bearing; \ Aiiiidota Sf). r.cptilos • 37. Birds , .18. Mammals. 3fi. Reptilia .37. Aves 38. ]\Iammalia MONOPHYLETIC PEDIGREE OF ANIMALS. ^33 EcMnoderma (^Stwr-fislies) Arthropoda {Articulated Animals) Tracheata Vertebrata {Yertehrated animals) Craniota Lipobrachia Crustacea I Annelida Mollnsca (Molluscs) Encephala Colobraohia Gephyrea Acrania Tunicata Acepliala Rotatoria Bryozoa I Vermes (Worms) CCEtOMATI (Worvis with a iody-cavity) Platyhelmlnthea Zoophyta ^" >■ ^ (Animal Plants) Acoelomi Spongia3 Acalephse (Worms without body-cavity) Protascua Prothelmig Protozoa. (Primarval anivials) Gastk^a PLANyEA Stkam (leptocardia) . Vcrtebrata without head, without skull and brain, without centralized heart. 1. SItuIMcSS I. Tabo-hearted [ i_ ^ancelet 1. Amphioxus II. animals toitifj slwlla (Craniota) and with tijicfesioalleli fjcatts (Pachycardia). Vertebrata with head, with ekoll and brain, with centralized heart. Main-classes of the Skulled, Anmuds. Classes of the Skulled Animals. Svi-classes of the Skulled Animals. Systematic Name of the Sub-classes. 2. Sinijlcs flflSftiltB Monorrhiaa 3. |ian=am» niotiatc Anamnion- ata 4. Stmnion animals Amnionata II. Bound mouths Cydostoma III. Fish Pisces IV. Mud .fish Dixineustd T. Sea.dragons HalisauH VI. Batrachiana Amphibia VII. Roptilea Reptilia> VIII. Birds Aves IX. Mammals Mammalia, 9. 10. II. 12. ^13. 14. 15. 16. 17. 18. 19. 20. i2\. 22. 23. Hags, or Mucous Fish Lampreys, or Pride Primseval fish Ganoid fiah Osseous fish Miid.fish Primaeval dragons Snake-dragons Fish-dragons Mailed Batra- chiana Naked Batra- chiana Primary reptiles Lizards Serpents Crocodiles Tortoises Flying reptiles Dragons Beaked reptiles Long-tailed Fan-tailed Bush- tailed 2. Hyperotreta (Myxinoida) 8. Hyperoartia (Fetromyzontia) 4. Selachii 5. Ganoides 6. Teleostei 7. Protopteri 8. Simosanria 9. Plesiosauria 10. lohthyosauria 11. Phraotamphibia 12. Lissamphibia 13. Tocosauria 14. Lacertilia 15. Opliidia 16. Crocodilia 17. Chelonia 18. Pterosauria 19. Diuosauria 20. Anomodojitia 21. Saurnrte 22. CarinatsB 23. Eatitaj 24. Cloaca! animals 2-1.. Monotrema 25. Pouched animals 25. Marsupialia 26. Placental animals 2G. Placeutalia PEDIGREE OF VERTEBRATES.- 205 9. Mammals Mainmalia 8. BirclB Aves 7. Eeptilea Reptilia 5. Sea-dragons Halisauria OsseonB fiah Teleostei Ganoid fish Ganoidei 4. Mnd-fish Dipneusta Amnion animals Amniota 6. BatracBians Amphibia Vertebrate animals breathing througli lnngB Amphipncumones Primaeval fish Selachii 3. Pishes Fisces ID(m6k=nOStriIcS Amphirrhina 2. Eonnd-mouthed Cyclostoma Sinalc-nasttilcS Monorrhina animals toiti) stalls ^ Craniota 1. Tube-hearted LeptocarAia, Sea-barrels Thaliacea Ascidicc SkulHcss animals Acrania Ucrtcbtatc animals Vertebrata Eicnuatcanimals Iimicata Worms Vermes 2o6 THE HISTORY OF CEEATION. sac, and a spleen. Further, all Double-nostriled animals possess a bladder-shaped expansion of the gullet, which, in Fish, has developed into the swimming bladder, but in all other Double-nostriled animals into lungs. Finally, in all Double-nostriled animals there exist in the youngest stage of growth the beginnings of two pairs of extremities, or limbs, a pair of fore legs, or breast fins, and a pair of hinder legs, or ventral fins. One of these pairs of legs sometimes degenerates (as in the case of eels, whales, etc.), or both pairs of legs (as in Csecilias and serpents) either degenerate or entirely disappear ; but even in these cases there exists some trace of their original beginning in an early embryonic period, or the useless remains of them may be found in the form of rudimentary organs. (Compare above, vol. i. p. 13.) From aU these important indications we may conclude with fuU assurance that aU double-nostriled animals are derived from a single common primary form, which developed either directly or indirectly during the primordial period out of the Monorrhina. This primary form must have possessed the organs above mentioned, and also the beginning of a swimming bladder and of two pairs of legs or fins. It is evident, that of all still living double-nostriled animals, the lowest forms of sharks are most closely allied to this long since extinct, unknown, and hypothetical primary form, which we may call the Primary Double- nostriled animals (Proselachii). We may therefore look upon the group of primeeval fish, or Selachii, to which the Proselachii probably belonged, as a primary group, not only of the Fish class, but of the whole main-class of double- nostriled animals. The class of Fish (Pisces) with which we accordingly PEIM.EVAL FISH. 207 begin the series of Double-nostriled animals, is distinguislied from the other six classes of the series by the swimming bladder never developing into lungs, but acting only as a hydrostatic apparatus. Agreeing with this, we find that in fish the nose is formed by two blind holes in front of the mouth, which never pierce the palate so as to open into the cavity of the mouth. In the other six classes of double-nostriled animals, both nostrils are changed into air passages which pierce the palate, and thus conduct air to the lungs. Genuine fish (after the exclusion of the Dipneusta) are accordingly the only double-nostriled animals which exclusively breathe through giUs and never . through lungs. In accordance with this, they aU live in water, and both pairs of their legs have retained the original form of paddling fins. Genuine fish are divided Into three distinct sub-classes, namely. Primaeval fish. Ganoid fish, and Osseous fiah. The oldest of these, where the original form has been most faithfully preserved, is that of the Frimceval fish (Selachii). Of these there still exist Sharks (Squali), and Rays (Rajoe), which are classed together as cross-mouthed fishes (Plagiostomi), and the strange and grotesquely formed Sea- cats, or Chirnmracei (Holocephali). These primary fish of the present day, which are met with in all seas, are only poor remains of the prevailing animal groups, rich in forms, which the Selachii formed in the earlier periods of the earth's history, and especially during the palaeolithic period. Unfortunately all Primseval fish possess a cartilaginous, never a completely osseous skeleton, which is but little, if at all, capable of being petrified. The only hard parts of the body which could be preserved in a fossil state, are the 208 THE HISTOKY OF CHEATION. SYSTEMATIC SURVEY Of the- 7 Legions and 15 Orders of the Fishes. Sub-classes of Fishes. Legions of Fishes. Orders of Fishes. E.tamples from the Orders. ^ ( |3timffiwl ^ JFisIj 1 I. Transverse months rlagiostomi ' 1. 2. Sharks Squalacei Hays Rajacei Sharks, dog-fish Spiked rays, electric rays, etc. Selachii II. Sea-Cata 3. Sea-Cats Chimoora, Calorrhyn- \ ^ MolocepliaU Chimm-acei chias III. Mailed Ganoid Pish ^ ■ 4. 5. Bnckler-heads Pamphracte Sturgeons Cephalaspidse, Placo- derma, etc. Spoon-sturgeons, stur- TaluUfiiri Sturiones gecns, sterlet, etc. B. ©aiiDili Jtsfj Ganoides IV. Angnlar-scalcd Ganoid Fish ^ Rhomhijeri 6. 7. 8. Efulcri Fulcrati Bemecopteri Double-firmed Palseoniscus, bony J)ike, etc. African finny pike, etc. Y. Ronnd-scaled Ganoid Fish Cydijen ■ 9. 10. Ccaloscolopes Pycnoscolopes Iloloptychius, Coelacan- thides, etc. Coccolepida, Amiadas, etc. C. ©SSC0U3 iFistj Teleostei 'VI. Osseons Fish with an air passage to the emmming bladder rhysostomi VII. Osseous Fish without an air 11. 12. '13. Herring species Thrisftogenes Eol species Enchchjgenes Siicliohranchii Herrings, salmon, carp, etc. Eels, snake eels, electric eels, etc. Perch, wrasse, turbot, etc. passage to the 14. Plcctognathi Trunk fish, globe fish, s%vinimiug etc. bladder 15. Lophohranchii Pipe fish, sea horses. ^, Physoclisti \ etc. PEDIGFtEE or THE NON-AMNIONATE CEANIOTA. 209 Anura Plectognathi LophobraTicTiia Stichobrfmchia Physoclisti Peromela Labyrintliodotita Soznia Enebelygenes Ganocephala Sozobranchia Fhractamphlbia Xissampliibia ThriBsogenes Pbysostomi Teleostei Pycnoscolopea CceloscoJopea Cycliferi (Cyologanoides) Semceoiiteri Amphibia Fulorati Pi-otopteri Efnicri Khombiferi (Ehomboganoides) Sturionea Ccphalaspidaj Pampbracti Tabnlifeii (Placoganoidos) Ganoides Squalacei Plaooderma Dipneusta Rajacei Plosio- sauria Icbthyo- sauria Simosanria Kalisauria Ampbipneumona ChimEei'acei Holocepbali Plagiostomi Selachii Fish Ampbirihina Cyclostoma Konorrhina Craniota 27 210 THE HISTORY OF CREATION. teeth and fin-spikes. These are found in the older formations in such quantities, varieties, and sizes, that we may, with certainty, infer a very considerable develop- ment of Primaeval fish m those remote ages. They are even found in the Silurian strata, which contain but few remains of other Vertebrata, such as Enamelled fish (and these only in the most recent part, that is, in the upper Silurian). By far the most important and interesting of the three orders of Primreval fish are Sharks; of all still living double-nostriled animals, they are probably most closely allied to the original primary form of the whole group, namely, to the Proselachii. Out of these Proselachii, which probably differed but little from genuine Sharks, Enamelled fish, and the present Primteval fish, in all prob- ability, developed in one direction, and the Dipneusta, Sea-dragons, and Amphibia in another. The Ganoid, or EnatiicLled fish (Ganoldes), in regard to their anatomy stand midway between the Prima3val and the Osseous fish. In many characteristics they agree with the former, and in many others with the latter. Hence, we infer that genealogically they form the transition from Primssval to Osseous fish. The Ganoids are for the most part extinct, and more nearly so than the Primeval fish, whereas they were developed in great force during the entire palaeolithic and mesolithic periods. Ganoid fish are divided into three legions according to the form of their external covering, namely, Mailed, Angular-scaled, and Round- scaled. The Mailed Ganoid fish (Tabuliferi) are the oldest, and are directly allied to the Selachii, out of which they originated. Fossil remains of them, though rare, are found even in the upper Silurian (Pteraspis ludensis of the GANOID AND BONY FISH. 211 Ludlow strata). Gigantic species of them, coated v/ltli strong bony plates, are found in the Devonian system. But of this legion there now lives only the small order of Sturgeons (Sturiones), including the Spade-sturgeons (Spatularidffi), and those Sturgeons (Accipenseridse) to which belong, among others, the Huso, which yields isinglass, or sturgeon's sound, and the Caviar-sturgeon, whose eggs we eat in the shape of caviar, etc. Out of the mailed Ganoid fish, the angular and round-scaled ones probably developed as two diverging branches. The Angular-scaled Ganoid fish (Rhombiferi) — which can be distinguished at first sight from all other fish by their square or rhombic scales — are at present represented only by a few survivors, namely, the Finny Pike (Polypterus) in African rivers (especially the Nile), and by the Bony Pike (Lepidosteus) in American rivers. Yet during the palsgolithic and the first half of the mesolithic epochs this legion formed the most numerous group of fishes. The third legion, that of Round-scaled Ganoid fish (Cycliferi), was no less rich in forms, and lived principally during the Devonian and Coal periods. This legion, of which the Bald Pike (Amia), in North American rivers, is the only survivor, was especially important, inasmuch as the third sub-class of fish, namely. Osseous fish, developed out of it. Osseous fish (Teleostei) include the greater portion of the fish of the present day. Among these are by far the greater portion of marine fish, and all of our fresh-water fish except the Ganoid fi:h just mentioned This class is distinctly proved by numerous fossils to have arisen about the middle of the Mesolithic epoch out of Ganoid fish, and moreover out of the Round-scaled, or Cycliferi. 212 THE HISTORY OF CREATION. The Thri^sopidce of the Oolitic period (Thrissops, Leptolepia, Tharsis), which are most closely allied to the herrings of the present day, are probably the oldest of all Osseous fish, and have directly arisen out of Round-scaled Ganoid fish, closely allied to the existing Amia. In the older Osseous fish of the legion called Pliysostomi, as also in the Ganoides, the swimming bladder throughout life was connected with the throat by a permanent air passage (a kind of windpipe). This is still the case with all the fish belonging to this legion, namely, with herrings, salmon, carp, shad, eels, etc. However, during the chalk period this air passage, in some of the Physostomi, became constricted and closed, and the swimming bladder was thus completely separated from the throat. Hence there arose a second legion of Osseous fish, the Physoclisti, which did not attain their actual development until the tertiary epoch, and soon far surpassed the Physostomi in variety. To this legion belong most of the sea fish of the present day, especially the large families of the Turbot, Tunny, Wrasse, Crowfiah, etc., further, the Lock-jaws (Plectognathi), Trunk fish, and Globe-fish and the Bushy -gills (Lophobranchi), viz.. Pipe-fish, and Sea-horses. There are, however, only very few Physoclisti among our river fish, for instance. Perch and Sticklebacks ; the majority of river fish are Physostomi. Midway between genuine Fish and Amphibia is the remarkable class of Mud-fish, or Scaly Sirens (Dipneusta, or Protopteri), There now exist only a few representatives of this class, namely, the American Mud-fish (Lepidosiren paradoxa) in the region of the river Amazon, and the African Mud-fish (Protopterus annectens) in different parts of Africa. A third large Salamander-fish (Ceratodus Foster!) THE DIPNEDSTA. 213 has lately been discovered in Australia. During the dry season, that is in summer, these strange animals bury themselves in a nest of leaves in the dry mud, and then breathe air through lungs like the Amphibia. But during the wet season, in winter, they live in rivers and bogs, and breathe water through gills like fish. Externally, they resemble fish of the eel kind, and are hke them covered with scales; in many other characteristics also — in their internal structure, their skeleton, extremities, etc. — they resemble Fish more than Amphibia. But in certain features they resemble the Amphibia, especially in the formation of their lungs, nose, and heart. There is consequently an endless dispute among zoologists, as to whether the Mud- fish are genuine Fish or Amphibia. Distinguished zoologists have expressed themselves in favour of both opinions But in fact, owing to the complete blending of character- istics which they present, they belong neither to the one nor to the other class, and are probably most correctly dealt with as a special class of Vertebrata, forming the transition between Fishes and Amphibians. The still living Dipneusta are probably the last surviving remains of a group which was formerly rich in forms, but has left no fossil traces on account of the want of a solid skeleton. In this respect, these animals are exactly like the Monor- rhina and the Leptocardia. However, teeth are found in the Trias which resemble those of the living Ceratodus. Possibly the extinct Dipneusta of the palEeolithic period, which developed in the Devonian epoch out of primaeval fish, must be looked upon as the primary forms of the Amphibia, and thus also of all higher Vertebrata, At all events the unkno^vn forms of transition — from Primaeval fish to Amphibia — were probably very like the Dipneusta. 2 14 THE HISTORY OF CREATIOlSr, A very peculiar class of Vertebrate animals, long since extinct, and which appears to have lived only during the secondary epoch, is formed by the remarkable Sea- dragons (Halisaiirla, or Enaliosauria, also called Nexipoda, or Swimming-footed animals). These formidable animals of prey inhabited the mesolithic oceans in great numbers, and wore of most peculiar forms, sometimes from thirty to forty feet in length. From many and excellently pre- served fossil remains and impressions, both of the entire body of Sea-dragons as well as of single parts, we have become very accurately acquainted with the structure of their bodies. They are usually classed among Reptiles, whilst some anatomists have placed them in a much lower rank, as directly allied to Fish. Gegenbaur's recently published investigations, which place the structure of their limbs in a true light, have led to the surprising conclusion that the Sea-dragons form quite an isolated group, differ- ing widely both from Reptiles and Amphibia as well as from Fish. The skeleton of their four legs, which are transformed into short, broad, paddling fins (like those of fish and whales) furnishes us with a clear proof that the Halisauria branched off from the main-stock of Verfcebrata at an earlier period than the Amphibia. For Amphibia, as well as the three higher classes of Vertebrata, are all derived from a common primary form, which possessed orAj five toes or fingers on each leg. But the Sea-dragons have (either distinctly developed or in a rudimentary condition as parts of the skeleton of the foot) more than five fingers, as have also the Selachians or Primeeval fish. On the other hand, they breathed air through lungs, like the Dipneusta, although they always swam about in the sea. They, ' THE SEA-DRAGOIfS. 215 therefore, perhaps, ia conjunction with the Dipnensta, branched off from the Selachii, but did not develop into higher Vertebrata ; they form an e::tinct lateral line of the pedigree, which has died out. The more accurately known Sea-dragons are classed into three orders, distinct enough one from the other, namely, PrimcGval Dragons, Fish Dragons, and Serpent Dragons. The PrimcBval Dragons (Simosauria) are the oldest Sea- dragons, and lived only during the Trias period. The skeletons of many different genera of them are met with in the German limestone known as " Muschel-kalk." They seem upon the whole to have been very like the Plesiosauria, and are, consequently, sometimes united with them into one order as Sauropterygia. The Serpent Dragons (Plesiosauria) lived in the oolitic and chalk periods together with the Iclithyosauria. They were characterised by an uncommonly long thin neck, which was frequently longer than the whole body, and carried a small head with a short snout. When their arched neck was raised they must have looked very like a swan ; but in place of wings and legs they had two pairs of short, flat, oval-paddling fins. The body of the Fish Dragons (Ichthyosauria) was of an entirely different form ; these animals may be opposed to the two preceding orders under the name of Fish- finners (Ichthyopterygia). They possessed a very long extended body, like a fish, and a heavy head with an elongated, flat snout, but a very short neck. Externally, they were probably very like porpoises. Their tail was very long, whereas it was very short in the members of the preceding orders. Also both pairs of paddling fins are 2l6 THE HISTORY OF CREATION', broader and show very different structure from that seen in the other two orders. Probably the Fish Dragons and Serpent Dragons developed as two diverging branches out of the Primaeval Dragons ; but it is also possible that the Plesiosauria alone originated out of the Simosauria, and that the Ichthyosauria were lower off-shoots from the common stock. At all events, they must all be directly, or indirectly derived from the Selachii, or Primseval fish. The succeeding classes of Vertebrata, the Am])hihia and the A mniota (Reptiles, Birds, and Mammals), owing to the characteristic structure which they all exhibit of five toes to each foot, may all be derived from a common primary form, which originated from the Selachii, and which possessed five toes on each of its four limbs. When we find a less number of toes than five, we can show that the missing ones must have been lost in the coiirse of time by adapta- tion. The oldest known Vertebrata with five toes are the BatracJiias (Amphibia). We divide this class into two sub-classes, namely, mailed Batrachians and naked Batrachians, the first of which is distinguished by tlie body being covered with bony plates or scales. The first and elder sub-class of Amphibia consists of the Mailed Batrachians (Phractamphibia), the oldest land living Vertebrata of which fossil remains exist. Well- preserved fossil remains of them occur in the coal, especially of those with Enamelled heads (Ganoeephala), which are most closely allied to fish, namely, the Archegosaurus of Saarbruck, and the Dendi-ei-peton of North America. There then follow at a later period the gigantic Labyrinth- toothed animals (Labyrinthodonta), which are represented in the Permian system by Zygosaurus, but at a later THE SALAMANDERS. 21 7 period, more especially in the Trias, by Mastodonsaurus, Trematosaurus, Capifcosaurus, etc. The shape of these formidable rapacious animals seems to have been between that of crocodiles, salamanders, and frogs, but in their internal structure they were more closely related to the two latter, while by their solid coat of mail, formed of strong bony plates, they resembled the first animals. These gigantic mailed Batrachians seem to have become extinct towards the end of the Triassic period. No fossil remains of mailed Batraehia are known during the whole of the subsequent periods. However, the still livuig blind Snakes, or Ccecilice (Peromela) — small-scaled Phractamphibia of the form and the same mode of life as the earth-worm — prove that this sub-class continued to exist, and never became completely extinct. The second sub-class of Amphibia, the naked Batraehia (Lissamphibia), probably originated even during the primary and secondary epochs, although fossil remains of them are first found in the tertiary epoch. They are distinguished from mailed Batraehia by possessing a naked smooth, and slimy skin, entirely without scales or coat of mail They probably developed either out of a branch of the Phractamphibia, or out of the same common root with them. The ontogeny of the three still living orders of naked Batraehia — the gilled Batraehia, tailed Batraehia, and frog Batraehia — distinctly repeats the historical course of de- velopment of the whole sub-class. The oldest forms are the gilled Batraehia (Sozobranchia), which retain throughout life the original primary form of naked Batraehia, and possess a long tail, together with water-breathing gills. They are most closely allied to the Dipneusta, from which. 2l8 THE HISTORY OF CKEATION, however, they differ externally by the absence of the coat of scales. Most gillcd Batrachia live in North America : among others of tlie class is the Axolotl, or Siredon, already mentioned. (Compare above, voL i. p. 241.) In Europe the order is only represented by one form, the celebrated " 01m" (Proteus angiiinus), which inhabits the grotto of Adelsberg and other caves in Carinthia, and which, from living in the dark, has acquired rudimentary eyes which can no longer see (voL i. p. 13). The order of Tailed Batrachia (Sozura) have developed out of the gilled Batrachia by the loss of external gills ; the order includes our black and yellow spotted land Salamander (Salamandra maculata), and pur nimble aquatic Salamandei-s (Tritons). Many of them — for instance, the celebrated giant Salamanders in Japan (Cryptobranchus Japonicus) — stUl retain the gill-slits, although the gills themselves have disappeared. All of them, however, retain the tail throughout life. Tritons occasionally — when forced to remain in water always — retain their gills, and thus remain at the same stage of development as gilled Batracliia. (Compare above, vol, i. p. 241.) The third order, the tailless or frog-like Batrachia (Anura), during their metamorphosis, not only lose their gills, with which in early life (as so-caUed tadpoles) they breathe in water, but also the tail with which they swim about. During their ontogeny, therefore, they pass through the course of development of the whole sub-class, they being at first Gilled Batrachia, then Tailed Batrachia, and finally Frog- like Batrachia. The inference from this is evidently, that Frog-like Batrachia developed at a later period out of Tailed Batrachia, as the latter had developed out of Gilled Batrachia which originally existed alone. THE AMNION-SAO. 219 In passing from the Amphibia to the next class of Vertebrata, namely, Reptiles, we observe a very considerable advance in the progress of organization. All the double- nostriled animals (Amphirrhina) up to this time considered, and more especially the two larger classes of Fish and Batrachia, agree in a number of important characteristics, which essentially distinguish them from the three remaining classes of Vertebrata — Reptiles, Birds, and Mammals. During tlie erabryological development of these latter, a peculiarly delicate covering, the first foetal membrane, or amnion, which commences at the navel, is formed round the embryo ; this membrane is filled with the amnion- water, and encloses the embryo or germ in the form of a bladder. On account of this very important and character- istic formation, we may comprise the three most highly developed classes of Vertebrata under the term AT^vnion- animals (Amniota). The four clas.ses of double-nostriled animals Avhich we have just considered, in which the amnion is wanting (as is the case in all lower Vertebrate animals, single-nostriled and skull-less animals), may on the other hand be opposed to the others as amnion-less animals (Anamnia). The formation of the foetal membrane, or amnion, which distinguishes reptiles, birds, and mammals from all other Vertebrata, is evidently a very imjJortant process in their ontogeny, and in the phylogeny which corresponds with it. It coincides with a series of other processes, which essentially determine the higher development of Amnionate animals. The first of these imjDortant processes is the total loss of gills, for which reason the Amniota, under the name of Gill-less animals (Ebranchiata), were fomierly 2 20 THE HISTORY OF CREATION. opposed to all other Vertebrate animals which breathed through gills (Branchiata). In all the Vertebrata already discussed, we found that they either always breathed through gills, or at least did so in early life, as in the case of Frogs and Salamanders. On the other hand, we never meet with a Reptile, Bird, or Mammal which at any period of its existence breathes through gills, and the gill- arches and openings which do exist in the embryos, are, during the course of the ontogeny, changed into entirely different structures, viz., into parts of the jaw-apparatus and the organ of hearing. (Compare above, vol. i. p. 307.) All Amnionate animals have a so-called cochlea in the organ of hearing, and a "round window" corresponding with it. These parts are wanting in the Amnion-less animals; moreover, their skull lies in a straight line with the axis of the vertebral column. In Amniotic animals the base of the skull appears bent in on the abdominal side, so that the head sinks upon the breast. (Plate III. Fig. 0, D, G, H.) The organs of tears at the side of the eye also first develop in the Amniota. The question now is. When did this important advance take place in the coxirse of the organic history of the earth ? When did the common ancestor of all Amniota develop out of a branch of the Non-amniota, to wit, out of the branch of the Amphibia ? To this question, the fossil remains of Vertebrata do not give us a very definite, but still they do give an approximate, answer. For with the exception of two lizard-like animals found in the Permian system (the Proterosaurus and Ehopalodon), all the fossil remains of Amniota, as yet known, belong to the secondary, tertiary, and quaternary epochs. With regard to the two Vertebrata THE TEIASSIC PERIOD. 221 just named, it is still doubtful whether they are genuine reptiles, or perhaps Amphibia of the salamander kind. Their skeleton alone is known to us, and even this not perfectly. Now as we know nothing of the characteristic features of their soft parts, it is quite possible that the Proterosaurus and Rhopalodon were non-amnionate animals more closely allied to Amphibia than to Reptiles ; possibly they belonged to the transition form between the two classes. But, on the other hand, as undoubted fossil remains of Amniota have been found as early as the Trias, it is probable that the main class of Amniota first developed in the Trias, that is, in the beginning of the Mesolithic epoch. As we have abeady seen, this very period is evidently one of the most important turning points in the organic history of the earth. The palaeolithic fern forests were then re- placed by the pine forests of the Trias period ; important transformations then took place in many of the classes of Invertebrata. Articulated marine lilies (Colocrina) (de- veloped out of the plated ones (Phatnocrina.) The Autechi- nidpe, or sea-urchins with only twenty rows of plates, took the place of the palasolithic Palechinidse, the sea-urchins with more than twenty rows of plates. The Cystidese, Blas- toidese, Trilobita, and other characteristic groups of Inverte- brata of the primary period became extinct. It is no wonder that transforming conditions of adaptation power- fully influenced the Vertebrate tribes also in the beginning of the Trias period, and caused the orij,ln of Amniotic animals. If, however, the two Lizard and Salamander-like animals of the Permian system, the Proterosaurus and Ehopalodon, are considered genuine Keptiles, and conse- 222 THE HISTORY OF CREATION. quently the most ancient Amniota, then the origin of this main class must necessarily have taken place in the preceding period, towards the end of the primary, namely, in the Permian period. However, all other remains of Reptiles, which were formerly believed to have been found in the Permian and the Coal system, or even in the Devonian system, have been proved to be either not remains of Reptiles at all, or to belong to a more recent date (for the most part to the Trias). (Compare Plate XIV.) The common hypothetical primary form of all Amniotic animals, which we may call Protaonnion, and which was possibly nearly related to the Proterosaurus, very probably stood upon the whole mid-way between salamanders and lizards, in regard to its bodily formation. Its descendants divided at an early period into two different lines, one of which became the common primary form of Reptiles and Birds, the other the primary form of Mammals. ■Of all the three classes of Amniota, Reptiles (Reptilia, or Pholidota, also called Sauria in the widest sense), remain at the lowest stage of development, and differ least from their ancestors, the Amphibia. Hence they were formerly uni- versally included among them, although their whole organization is much more like that of Birds than Amphibia. There now exist only four orders of Reptiles, namely, — Lizards, Serpents, Crocodiles, and Tortoises. They, however foi-m but a poor remnant of the exceedingly various and higlily developed host of Reptiles which lived during the Mesolithic, or Secondary epoch, and predominated over all other Vertebrata. The immense development of Reptiles during tlie Secondary epoch is so characteristic that we could as well name it after those animals as after the tiaeclcel_ History of CreaHorii Branches, Classes, and Sofa-Classes, oftije\%it)ebrate Stem. Prochordata EvErtebrate Forefkthens of the VertcJ>rate SkuU-less (Acrajoia) or ■fiibeiearted (lepto- cardia) Single mostrilled (Manorfrina) I Tviai gills, without Amnion. Fl. JW. A mniota Paired nostrilled or Amphirrhina with Amnion, without gills. KECENT AND FOSSIL REPTILES. 223 Gymnosperms (p. 111). Twelve of the twenty-seven sub- orders, given on the aceompanjdng table, and four of the eight orders, belong exclusively to the secondary period. These mesolithic groups are marked by an asterisk. AU the orders, with the exception of Serpents, are found fossil even in the Jura and Trias periods. In the first order, that of Primary Reptiles, or Prim/i.ry Creepers (Tocosauria), we class the extinct Thecodontia of the Trias, together with those Eeptiles which we may look upon as the common primary form of the whole class. To the latter, which we may call Frimceval lieptiles (Proreptilia), the Proterosaurus of the Permian system very probably belongs. The seven remaining orders must be considered as diverging branches, which have developed in different directions out of that common primary form. The Thecodontia of the Trias, the only positively known fossil forms of Tocosauria, were Lizards which seem to have been like the still living monitor lizards (Monitor, Varanus). Of the four orders of reptiles now existing, and which, moreover, have alone represented the class since the beginning of the tertiary epoch, that of Lizards (Lacertilia) is probably most closely allied to the extinct Primary Reptiles, and especially through the monitors already named. The class of Serpents (Ophidia) developed out of a branch of the order of lizards, and this probably not until the beginning of the tertiary epoch. At least we at present only know of fossil remains of ser23ents from the tertiary strata. Crocodiles (Ci'oeodilia) existed much earlier ; the Teleosauria and Steneosauria belonging to the class are found fossil in large quantities even in the Jura ; but the 224 THE HISTOEY OF CEEATTON. SYSTEMATIC SUKVEY Of the 8 Orders and 27 Sub-orders of Beptiles. (Those groups marked with * became extinct even during the Secondary Period.) Orders of Iteptiles. SuXi-orders of Heptiles. Si/stematic Name of the Sub-orders. A Generic Name an example. I. primarg Kcptilcs Tocosauria 1 , 2 PrimfcBval rep- tiles 1. Proreptilia 2. Thecodontia * (Proterosaurns ? * Palaeosaurna ' 3 Cleft-tongned 3. Fissilingnes Monitor II. iLtjarts Lacertilia 4. Thick-tongued 4. Crassilinguoa Ignana 5 Short-tongned 5. Brevilingnes Anguis 6. Einged lizards 6. Glj'ptodermata Amphisbasna , 7. Chameleons 7. Vcrmilingues Chamseleo ■ 8. Adders 8. Aglyphodonta Coluber 9. Tree serpents 9. Opisthoglj'pha Dipsas III. Serpents . Ophidia 10. 11. Vipers 10. Proteroglypha 11. Solenoglypha Hydrophis Vipera .12. Worm serpents 12. Opoterodonta Typhlops lY. QLxata' ( ^^■ Amphicoela 13. Teleosanria * Teleosaoms iilcs • l-l- Opisthocoela 14. Stcneosanria * Steneosatnus Crocodilia \ ^^■ Prosthocoela 15. Alligatores Alligator /16. Sea tortoises 16. Thalassita Chclone V. Eortoiscs 17. Eiver tortoises 17. Potamita Trionyx Chelonia 18. Marsh tortoises 18. Elodita Emys 19. Land tortoises 19. Chersita Testndo VI. jrigins 3aEptiIc3 - Pterosanria * 20. 21. Long-tailed Flying lizards Short-tailed Flying lizards 20. Ehampho- rhynchi 21. Pterodactyli * Ehampho- rhynchus * Pterodactylus VII. Sratjons Dinosauria * 22. 23. Giant dragons Elephantine dragons 22. Harpagosauria 23. Therosanria * Megalosanrua * Ignanodon 24. Dog-toothed 24. Cynodontia * Dicynodon VIII. 33cakctl 25. Toothless 25. Cryptodontia * Udenodon aStptiks 26. Kangaroo rep- 26. Hypsosauria * Compsognathns Anomodontia * 27. tiles Bird reptiles 27. Tooornithes * (Tocomis) BIRD-LIKE REPTILES. 225 still living alligators are first met with in a fossU state in the chalk and tertiary strata. The most isolated of the four existing orders of reptiles consists of the re- markable group of Tortoises (Chelonia) ; fossils of these strange animals are first met with in the Jura. In some characteristics they are allied to Amphibia, in others, to Crocodiles, and by certain peculiarities even to Birds, so that their true position in the pedigree of Eeptiles is probably far down at the root. The extraordinary re- semblance of their embryos to Birds, manifested even at later stages of the ontogenesis, is exceedingly striking. The four extinct orders of Eeptiles show among one another, and, with the four existing orders just mentioned, such various and complicated relationships, that in the present state of our knowledge we are obliged to give up the attempt at establishing their pedigree. The most deviating and most curious forms are the Flying Reptiles (Pterosauria) ; flying lizards, in which the extremely elon- gated fifth finger of the hand served to support an enormous flying membrane. They probably flew about, in the secondary period, much in the same way as the bats of the present day. The smallest flying lizards were about the size of a sparrow ; the largest, however, with a breadth of wino" of more than sixteen feet, exceeded the largest of our living flying birds in stretch of wing (condor and albatross). Numerous fossil remains of them, of the long-tailed Rham- phorhynchia and of the short-tailed Pterodaetylfe are found in all the strata of the Jura and Chalk periods, but in these only. Not less remarkable and characteristic of the Mesolithic epoch was the group of Dragons (Dinosauria, or Pachypoda). 2 26 THE HISTORY OF CEEATION. These colossal reptiles, which attained a length of more than fifty feet, are the largest inhabitants of the land which have ever existed on our globe ; they lived exclusively in the secondary epoch. Most of their remains are found in the lower cretaceous system, more especially in the Wealden formations of England. The majoiity of them were fearful beasts of prey (the Megalosaurus from twenty to thirty, the Pclorosaurus from forty to fifty feet in length). The Iguanodon, however, and some others lived on vegetable food, and probably played a part in the forests of the chalk period similar to that of the unwieldy but smaller elepliants, hippopotami, and rhinoceroses of the present day. The Beaked Beptiles (Anomodontia), likewise also long since extinct, but of which very many remarkable remains are found in the Trias and Jura, were perhaps closely related to the Dragons. Their jaws, like those of most Flying Reptiles and Tortoises, had become changed into a beak, which either possessed only degenerated rudimentary teeth, or no teeth at alL In this order, if not in the preceding one, we must look for the primary parents of the bird class, which we may call Bird Reptiles (Tocornithes). Probably very closely related to them was the curious, kangaroo-like Compsognathus from the Jura, which in very important characteristics already shows an approximation to the structure of birds. The class of Birds (Aves), as ah-eady remarked, is so closely allied to Reptiles in internal structure and by embryonal development, that they undoubtedly originated out of a branch of this class. Even a glance at Plates II. and III. will show that the embryos of birds at a time \^'hen they already essentially difier from the embryos of THE UEPTILE-LIKE BIRD. 227 Mammals, are still scarcely distinguishable from those of Tortoises and otlier Reptiles. The cleavage of the yolk is partial in the case of Birds and Reptiles, in Mammals it is total. The red blood-cells of the former possess a kernel, those of the latter do not. The hair of Mammals develops in closed follicles in the skin, but the feathers of birds and also the scales of reptiles develop in hillocks on the skin. The lower jaw of the latter is much more complicated than that of Mammals ; the latter do not possess the quadrate bone of the formej?. Whereas in Mammals (as in the case of Amphibia) the connection between the skull and the fii-st neck vertebra is formed by two knobbed joints, or condyles, in Birds and Reptiles these have become united into a single condyle. The two last classes may therefore justly be united into one group as Monocondylia, and contrasted to Mammals, or Dicondylia. The deviation of Birds from RejjtUes, in any case, first took place in the mesolithic epoch, and this moreover probably during the Trias. The oldest fossU remains of birds are found in the upper Jura (Archjeopteryx). But there existed, even in the Trias period, different Saurians (Anomodonta) which in many respects seem to form the transition from the Tocosauria to the primary ancestors of Birds, the hypothetical Tocornithes. Probably these Tocor- nithes were scarcely distinguishable from other beaked lizards in the system, and were closely related to the kangaroo-Uke Compsognathus from the Jura of Solenhofen. Huxley classes the latter with the Dinosauria, and believes them to be the nearest relations to the Toconiithes. The great majority of Birds — in spite of all the variety in the colouring of their beautiful feathery dross, and in the 2 28 THE HISTORY OF CREATION. formation of their beaks and feet — are of an exceeedingly uniform organization, in much the same way as are the class of insects. The bird form has adapted itself on all sides to the external conditions of existence, without having thereby in any way essentially deviated from the strict hereditary type of its characteristic structure. There are oidy two small groups, the feather-tailed birds (Saururse) and those of the ostrich kind, which differ considerably from the usual type of bird, namely, from those with keel-shaped breasts (Carinat^), and hence the whole class may be divided into three sub-classes. The first sub-class, the Reptile-tailed, or Feather-tailed Birds (Saururse), are as yet known only through a single, and that an imperfect, fossil impression, which, however, in being the oldest and also a very peculiar fossil bird, is of great importance. This fossil is the Primasval Griffin, or Arch83opteryx lithographica, of which as yet only one speci- men has been found in the lithographic slate at Solenhofen. in the Upper Jura system of Bavaria. This remarkable bird seems on the whole to have been of the size and form of a large raven, especially as I'egards the legs, which are in a good state of preservation ; head and breast unfortun ately are wanting. The formation of the wings deviates somewhat from that of other birds, but that of the tail still more so. In all other birds the tail is very short and composed of but few short vertebrae ; the last of these have grown together into a thin, bony plate standing pei-pen- dicularly, upon which the rudder-feathers of the tail are attached in the form of a fan. The Archteopteiyx, however has a long tail like a lizard, composed of numerous (20) long thin vertebras, and on every vertebra are attached the SDB-CLASSES OF BIRDS. 229 strong rudder-feathers in twos, so that the whole tail appears regularly feathered. This same formation of the tail part of the vertebral column occurs transiently in the embryos of other birds, so that the tail of the Archteopteryx evidently represents the original form of bird-tail inherited from reptiles. Large numbers of similar birds with lizard- tails probably lived during the middle of the secondary period ; accident has as yet, however, only revealed this one fossil. The Fan4ailed, or Keel-hreccsted birds (CarinatiB), which form the second sub-class, comprise all living Birds of the present day, with the exception of those of the ostrich kind, or Eatitse. They probably developed out of Feather- tailed Birds during the first half of the secondary period, namely, in the Jura or chalk period, by the hinder tail vertebrae growing together, and by the tail becoming shortened. Only very few remains of them are known from the secondary period, and these moreover only out of the last section of it, namely, from the Chalk These remains belong to a swimming bird of the albatross species, and a wading bird like a snipe. All the other fossil remains of birds as yet known have been found in the tertiary strata. The Bushy-tailed, or Ostrich-Woe Birds (Ratitse), also called Running Birds (Cursores), the third and last sub- class, is now represented only by a few living species, by the African ostrich with two toes, the American and Australian ostrich with three toes, by the Indian cassowary and the four-toed kiwi, or Apteryx, m New. Zealand. The extinct giant birds of Madagascar (iEpyornis) and the New Zealand Dinornis, which were much larger than the 230 THE HISTORY OF CREATION. still living ostriches, also belong to this group. The Birds of the ostrich kind — by giving up the habit of flying, by the degeneration of the muscles for flying resulting from this, and of the breast bone which serves as their support, and by the corresponding stronger development of the hinder legs for running — have probably arisen out of a branch of the Keel-breasted birds. But possibly, as Huxley thinks, they may be the nearest relations of the Dinosauria and of the Reptiles akin to them, especially of the Compsognathus ; at all events, the common primary foim of all Birds must be looked for among the extinct Reptiles. CHAPTEE, XXI PEDIGREE AND HISTORY OF THE ANIMAL KINGDOM, IV. Mammals. The System of Mammals according to Linnasns and Blainville. — Three Sab-classea of Mammals (Ornithodelphia, Didelphia, Monodelphia). — Omithodelphia, or Monotrema, — Beaked Animals (Ornithostoma). — Didelphia, or Marsupials. — Herbivorous and CarniTorons Marsupials. — Monodelphia, or Placentalia (Placental Animals). — Meaning of the Placenta. — Tnft Placentalia.^Girdle Placentalia. — Disc Placentalia. — Non-deciduates, or Indeciduata. — Hoofed Animals. — Single and Double- hoofed Animals. — "Whales. — Toothless Animals. — Deciduates, or Animals with Decidua. — Semi.apes. — Gnawing Animals. — Pseudo-hoofed Ani- mals. — Inseotivora. — Beasts of Prey. — Bats. — Apes. There are only a few points in the classification of organisms upon wbich naturalists have always agreed. One of these few undisputed points is the privileged position of the class of Mammals at the head of the animal kingdom. The reason of this privilege consists partly in the special interest, also in the various uses and the many pleasures, which Mammals, more than all other animals, offer to man, and partly in the circumstance that man himself is a member of this class. For however differently in other respects man's position in nature and in the system of animals may have been regarded, yet no naturalist has ever doubted that man, at least from a purely 232 THE HISTOEY OF CREATION. morphological point of view, belongs to the class of Mam- mals. From this there directly follows the exceedingly important inference that man, by consanguinity also, is a member of this class of animals, and- has historically developed out of long since extinct forms of Mammals. This circumstance alone justifies us Jiere in turning our especial attention to the history and the pedigree of Mammals. Let us, therefore, for this purpose first examine the groups of this class of animals. Older naturalists, especially considering the formation of the jaw and feet, divided the class of Mammals into a series of from eight to sixteen orders. The lowest stage of the series was occupied by the whales, which seemed to differ most from man, who stands at the highest stage, by their fish-like form of body. Thus Linnceus distinguished the following eight orders : (1) Cetse (whales) ; (2) BeUuce (hippopotami and horses) ; (3) Pecora (ruminating animals) ; (4) Glires (gnawing animals and rhinoceroses) ; (5) Bestife (insectivora, marsupials, and various others) ; (6) Fera3 (beasts of prey) ; (7) Bruta (tootliless animals and elephants) ; (8) Primates (bats, semi-apes, apes, and men). Cuvier's classification, which became the standard of most subsequent zoologists, did not rise much above that of Linnteus. Cuvier distinguished the following eight orders : (1) Cetacea (whales) ; (2) Euminantia (ruminating animals) ; (3) Pachyderma (hoofed animals, with the exclusion of ruminating animals) ; (4) Edentata (animals poor in teeth) ; (5) Rodentla (gnawing animals) ; (6) Carnassia (marsupials, beasts of prey, insectivora, and bats); (7) Quadrumana (semi-apes and aj)cs) ; (8) Bimana (man). The most important advance in the classification of THE CLOACAL, MAMMALS. 233 Mammals was made as early as 1816 by the eminent anatomist Blainville, who has ah-eady been mentioned and who fii'st clearly recognised the three natural main groups or sub-classes of Mammals, and distinguished them aceordiEg to the formation of their generative organs as Ornitliodelphia, JDidelphia, and Monoclelphia. As this division is now justly considered by all scientific zoologists to be the best, on account of solid foundation on the history of development, let us here keep to it also. The first sub-class consists of the Cloacal Aninmls, or Breastless anivials, also called Forked animals (Monotrema, or Ornitliodelphia). This class is now represented only by two species of living mammals, both of which are confined to Australia and the neighbouriug island of Van Diemen's land namely, the well-known Water Duck-bill (Omithorhynchus paradoxus) with the beak of a bird, and the less known Beaked Mole (Echidna hystrix), resembHiig a hedgehog. Both of these curious animals, which are classed in the order of Beaked Animals (Ornithostoma), are evidently the last surviving remnants of an animal group formerly rich in forms, which alone represented the Mammalia in the secondary epoch, and out of which the second sub-class, the Didelphia, developed later, probably in the Jurassic period. Unfortunately, we as yet do not know with certainty of any fossil remains of this most ancient primary group of Mammals, which we wiU caU Primary Mammals (Pro- mammalia). Yet they possibly comprise the oldest of all the fossil Mammalia known, namely, the Microlestes antiquus, of which animals, however, we as yet only know some few small molar teeth. These have been found in the upper- most strata of the Trias, in the Keuper, first in Ger- 28 234 THE HISTOCY OF CREATION. many (at Degerlocli, near Stuttgart, in 1847), later also in England (at Frome), in 1858. Similar teeth have lately been found also in the North American Trias, and have been described as Dromatherium sylvestre. These remarkable teeth, from the characteristic form of which we can conclude that they belonged to an insectivorous mammal, are the only remains of mammals as yet found in the older secondary strata, namely, in the Trias. It is possible, however, that besides these many of the other mammalian teeth found in the Jura and Chalk systems, which are still generally ascribed to Marsupials, in reality belong to Cloacal Animals. This cannot be decided with certainty owing to the absence of the characteristic soft parts. In any case, numerous Monotrema, with well-developed teeth and cloaca, must have preceded the advent of Marsupial animals. The designation, " Cloacal animals" (Monotrema), has been given to the Ornithodelphia on account of the cloaca which distinguishes them from all other Mammals; but winch on the oiber hand makes them agree with Birds, Reptiles, and Amphibia, in fact, with the lower Vertebrata. The formation of the cloaca consists in the last portion of the intestinal canal receiving the mouth of the uroo-enital apparatus, that is, the united urinary and genital organs, whereas in all other Mammals (Didelphia as well Mono- delphia) these organs have an opening distinct from that of the rectum. However, in these latter also the cloaca formation exists during the first period of their embryonal life, and the separation of the two openings takes place only at a later date (in man about the twelfth week of develop- ment). The Cloacal animals have also been called " Forked animals" because the coUar-bones, by means of the breast CHARACTERS OF MONOTllEMA. 235 bone, have become united into one piece, similar to the well- known fork-bone, or meiTy-thought, in birds. In all other Mammals the two collar-bones remain separated in front and do not fuse with the breast bone. Moreover, the coracoid bones are much more strongly developed in the Cloacal animals than in the other Mammalia, and are con- nected with the breast bone. In many other characteristics also — especially in the formation of their internal genital organs, their auricular labyrinth, and their brain — Beaked animals are more closely allied to the other Vertebrata than to Mammals, so that some naturalists have been inclined to separate them from the latter as a special class. However, like all other Mammals, they bring forth living J'oung ones, which for a time are nourished with milk from the mother. But whereas in all other Mammals the milk issues through nipples, or teats, from the mammary glands, teats are completely wanting in beaked animals, and the milk comes simply out of a flat, sieve-like, perforated patch of the skin. Hence they may also be called Breastless or Teatless aninnals (Amasta). The curious formation of the beak in the two still living Beaked animals, which is connected T^^ith the suppression of the teeth, must evidently not be looked upon as an essential feature of the whole sub-class of Cloacal animals, but as an accidental character of adaptation distinguishing the last remnant of the class as much from the extinct' main group, as the formation of a similar toothless snout dis- tinguishes many toothless animals (for instance, the ant- eater) from the other placental animals. The unknown, extinct Primary Mammals, or Promammalia — which lived during- the Trias period> and of which the two stiU living 236 THE mSTOEY OF CEBATION. orders of Beaked animals represent but a single degenerated branch developed on one side — probably possessed a very highly developed jaw like the marsupial animals, which developed from them. Marsupial, or Pouched Animals (Didelphia, or Marsu- pialia), the second of the three sub-classes of Mammals, form in every respect — both as regards their anatomy and embryology, as well as their genealogy and history — the transition between the other sub-classes — the Cloacal and Placental Animals. Numerous representatives of this group still exist, especially the well-known kangaroos, pouched rats, and pouched dogs ; but on the whole this sub-class, like the preceding one, is evidently approaching its complete extinction, and the living members of the class are the last surviving remnants of a large group rich in forms, which represented the Mammalia during the more recent secondary and the earlier tertiary periods. The Marsupial Animals probably developed towards the middle of the Mesolithic epoch (during the Jura) out of a branch of the Cloacal Animals, and in the beginning of the Tertiary epoch again, the group of Placental Animals arose out of the Marsupials, and the latter then succumbed to the former in the struggle for life. All the fossil remains of Mammals known to us from the Secondary epoch, belong either exclusively to Marsupials, or partly perhaps to Cloacal animals. At that time Marsu- pials seem to have been distributed over the whole earth ; even in Europe (France and England), well-preserved fossil remains of them have been found. On the other hand, the last off-shoots of the sub-class now living are confined to a very nan-ow tract of distribution, namely, to Australia, the Australasian, and a small part of the Asiatic, Archipelago. THE POUCHED MAMMAIS. 237 There are also a few species still living in America, but at the present day not a single marsupial animal lives on the continent of Asia, Africa, or Europe. The name of pouched animals is given to the class on account of the purse-shaped pouch (marsupium) existing in most instances on the abdominal side of the female animals, in which the mother carries about her young for a considerable time after their birth. This pouch is supported by two characteristic marsupial bones, also existing in Cloacal animals, but not in Placental animals. The young Marsupial animal is bom in a much more imperfect form than the young Placental animal, and only attains the same degree of development which the latter possesses directly at its birth, after it has developed in the pouch for some time. In the case of the giant kangaroo, which attains the height of a man, the newly born yoxm n, Plate VIII.), that their crustacean nature was proved. Our drawing shows a "duck mussel " of the natural size, from the right side. The right half of the bivalved shell has been removed, so that the body is seen lying in the left half of the shell. From the rudimentary head of the Lepas there issues a long, fleshy APPENDIX. 393 stalk (curving upwards in onr drawing) ; hj means of it the Barnacle crab grows on rocks, ships, etc. On the ventral side are six pairs of feet. Every foot is forked and divided into two long, curved, or curled " tendrils " furnished with bristles. Above and behind the last pair of feet projects the thiu cylin- drical tail. Fig. E c represents a parasitic sack-crab (Sacculina purpurea) from the order of Eoot-crabs (Rhizocephala). These parasites, by adaptation to a parasitical life, have developed out of Barnacle crabs (Fig. D c), much in the same way as the fish-lice (C c), out of the freely swimming Oar-legged crabs (U c). However, the suppression, and the subsequent degeneration, of all of the organs, has gone much further in the present case than in most of the fish-lice. Out of the articulated crab, possessing legs, intestine, and eye, and which in an early stage as nauplius (.B m, Plate VIII.), swam about freely, there has developed a formless, unsegmented sack, a red sausage, which now only contains sesual organs (eggs and sperm) and an intestinal rudiment. The legs and the eye have completely disappeared. At the posterior end is the opening of the genitals. From the mouth grows a thick bunch of numerous tree-shaped and branching root-like fibres. These spread themselves out (like the roots of a plant in the ground) in the soft hinder part of the body of the hermit- crab (Pagurus), upon which the root-crab lives as a parasite, and from which it draws its nourishment. Oar drawing (^ c), a copy of Fritz Miiller's, is slightly enlarged, and shows the whole of the sausage-shaped sack-crab, with aU its root-fibres, when di-awn out of the body upon which it lives. Fig. i*" c is a shriinp (Peneus Miilleri), from the order of ten-foot crabs (Decapoda), to which our river cray-fish, and its nearest relative, the lobster, and the short-tailed shore-crabs also belong. This order contains the largest and, gastronomically, the most im- portant crabs, and belongs, together with the mouth-legged and split-legged crabs, to the legion of the stalk-eyed mailed crabs (Podophthalma). The shrimp, as well as the river crab, has in front, on each side below the eye, two long feelers (the first 394 APPENDIX. much shorter than the second), then three jaws, and three jaw- feet, then five very long legs (the three fore ones of which, in the Penens, are furnished with nippers, and the third of which is the longest). Finally, on the first five joints of the hinder part of the body there are other five pairs of feet. This shrimp, which is one of the most highly develojied and perfect crabs, originates (according to Fritz Miiller's important discovery) out of a nauplius (_F n Plate VIII.), and consequently proves that the higher Crustacea have developed out of the same form as the lower ones, namely, the nauplius. (Compare voL ii. p. 176). Plates XII. anb XIII. {Between pages 200 and, 201, Vol. II.) Blood relaiionsMp hehveen ihe Veriehrata and the Inveriehrata. (Compare vol. ii. pp. 152 and 201.) It is definitely estabHshed by Kowalewski's important discovery, which was confirmed by Kupflier, that the ontogeny of the lowest vertebrate animal — the Lancelet, or Amphioxus — agrees in all essential outlines com- pletely with that of the invertebrate Sea-squirts, or Ascidia?, from the class of Sea-sacks, or Tunicata. On our two plates, the ascidia is marked by A, the amphioxus by B. Plate XIII. represents these two very different animal-forms in a fully developed state, as seen from the left side, the end of the mouth above, the opposite end below. Hence, in both figures the dorsal side is to the right, the ventral to the left. Both figures &ve slightly magnified, and the internal organisation of the animals is distinctly visible through the transparent skin. The full- grown ascidia (Pig. A 6) gi'ows at the bottom of the ocean, from whence it cannot move, and clings to stones and other objects by means of peculiar roots (w) like a plant. The full- grown amphioxus, on the other hand (Fig. B 6), swims about freely like a small fish. The letters on both figures indicate the same parts : (a) orifice of the mouth ; (6) orifice of the body, or porus abdominalis ; (c) dorsal rod, or chorda dorsalis ; (d) intes- tine ; (e) ovary ; (/) oviduct (same as the sperm-duct) ; (g) spinal marrow t (h) heart; (i) blind-sao of the intestine; (le) giU APPENDIX. 395 basket (respiratory cavity) ; (I) cavity of tlie body ; (m) muscles ; (n) testicle (in the ascidia united witt the ovary into a herma- pbrodite gland) ; (o) anus ; (p) genital orifice ; (g) well-developed embryos in the body cavity of tbe ascidia; (r) rays of tlie dorsal fin of the amphioxus ; (s) tail-fin of the amphioxus ; (zv) roots of the ascidia. Plate XII. shows the Ontogenesis, or the individual development of the Ascidia {A) and the A'npliioxus (U) in five different stages (1-5). Fig. 1 is the egg, a simple cell like the egg of man and all other animals (Fig. A 1 the egg of the ascidia, Fig. B 1 the egg of the amphioxus). The actual cell-substance, or the protoplasm of the egg-cell (z), the so-called yolk, is sur- rounded by a covering (cell-membrane, or yolk-membrane), and encloses a globular cell-kernel, or nucleus (y), the latter, again, contains a kernel-body, or nucleolus (a;) ; when the egg begins to develop, the egg-cell first subdivides into two cells. By another sub-division there arise four cells (Fig. A2, B 2), and out of these, by repeated sub-division, eight cells (vol. i. p. 190, Fig. 4 G, D). By 11 aid gathering in the interior these form a globular bladder bounded by a layer of cells. On one spot of its surface the bladder is turned inwards in the form of a pocket (Fig. A 4<, B 4), This depression is the beginning of the intestine, the cavity (d 1) of which opens externally by the provisional larval-mouth {d 4). The body-wall, which is at the same time the stomach-wall, now consists of two layers of cells — the germ-layers. The globular larva (Gastrula), now grows in length. Fig. A 5 represents the larva of the ascidia. Fig. B 6 that of the amphioxus, as seen from the left side in a somewhat more advanced state of development. The orifice of the intestine (d 1) has closed. The dorsal side of the intestine (d 2) is con- cave, the ventral side (d 3) convex. Above the intestinal tube, on its dorsal side, the neural tube, the beginning of the spinal m.arrow, is being formed, its cavity still opens externally in front (g 2). Between the spinal marrow and the intestine has arisen the spinal rod, or chorda dorsalis (Notochord) (c), the axis of the inner skeleton. In the lai'va of the ascidia this rod (c) proceeds 396 APPENDIX. along tlie long rudder-tail, a larval organ, wMch is cast off in later transformation. Yet there still exist some very small ascidise (Appendicnlaria) wliicli do not become transformed and attaclied, but which through life swim about freely in the sea by m.eans of their rudder-tail. The ontogenetic facts which are systematically represented on. Plate XII. and which were first discovered in 1867, deserve the greatest attention, and, indeed, cannot be too highly estimated. They fill up the gap which, according to the opinion of older zoolo- gists existed between the vertebrate and the so-called " inverte- brate " animals. This gap was universally regarded as so im- portant and so undeniable, that even eminent zoologists, who were not disinclined to adopt the theory of descent, saw in this gap one of the chief obstacles against it. Now that the ontogeny of the amphioxus and the ascidia has set this obstacle completely aside, we are for the first time enabled to trace the pedigree of man beyond the amphioxus into the many-branching tribe of "invertebrate " worms, from which all the other higher animal tribes have originated. If our speculative philosophers. Instead of occupying them- selves with castles in the air, were to give their thoughts for some years to the facts represented on Plates XII. and XIII., as well as to those on Plates II. and III., they would gain a foundation for true philosophy — for the knowledge of the universe firmly based on experience — which would be sure to influence all regions of thought. These facts of ontogenesis are the in- destructible foundations upon which the monistic philosophy of future times will erect its imperishable system, Plate XIV. (Between pages 206 and 207, Vol. 11.) Monojpliyletic, or One-rooted Pedigree of tlie Verteirate Animal tribe, representing the hypothesis of the common derivation of all vertebrate animals, and the historical development of their different classes during the palasontological periods of the earth's history. (Compare Chapter XX. vol. ii. p. 192.) The horizontal APPENDIX. 397 lines indicate the periods (mentioned in vol. ii. p. 14) of tlic organic history of the earth during which the deposition of the strata con- taining fossils took place. The vertical lines separate the classes and sub-classes of vcrtehrata from one another. The tree-shaped and hranching lines, by their greater or lesser number and thick- ness, indicate the approsimate degree of development, variety, and perfection, which each class probably attained in each geological period. In those classes which, on account of the soft nature of their bodies, could not leave any fossil remains (which is especially the case with Prochordata, Acrania, Monorrhina, and Dipneusta) the course of development is hypothciically suggested on the ground of arguments derived from the three records of creation — comparative anatomy, ontogeny, and palaeontology. The most important starting-points for the hypothetical completion of the palreontological gaps are here, as in all cases, furnished by the fundaimental law of biogeny, which asserts the inner ca/usal- nexus existing between ontogeny and phylogeny. (Compare vol. i. p. 310, and vol. ii. p. 200 ; also Plates VIII.— XIII.) In all cases we have to regard the individual development (determined by the laws of Inheritance but modified by the laws of Adaptation) as short and quick repetitions of the paloeontological development of the tribe. This proposition is the " ceteram censeo " of our theory of development. The statements of the first appearance, or the period of the origin of the individual classes and sub-classes of vertebrate animals (apart from the hypothetical filling in mentioned just now), are taken as strictly as possible from palseontological facts. It must, however, be observed, that in reality the origin of most of the groups probably took place pne or two periods earlier than fossils now indicate. In this I agree with Huxley's views ; but on Plates V. and XIV. I have disregarded this con- sideration in order not to go too far from patoontological facts. The numbers signify as follows (compare also Chapter XX. and vol. ii. pp. 204, 206) : — 1. Animal Monera ; 2. Animal Amcebse ; 3. Community of Amoebae (Synamoebae) ; 4. Ciliated Infusoria without mouths ; 5. Oihated Infusoria with mouths ; 6. Gliding 398 APPENDIX. worms (Turbellaria) ; 7. Sea-sacks (Tnnicata) ; 8. Lancelet (AmpTiioxus) ; 9. Hag (Myxinoida) ; 10. Lamprey (Petro- myzontia) ; 11. Unknown forms of transition from single- nostriled animals to primajval fislies; 12. Silurian primseval fisk (Onclius, etc.); 13. Living primaeval fiskes (skarks, rays, Chimasrffi) ; 14. Most ancient (Silurian) enamelled fiskes (Pteraspis); 15. Turtle fiskes (Pampkracti) ; 16. Sturgeons (Sturiones) ; 17. Ajigular-scalcd enamelled fiskes (Rkom- biferi) ; 18. Bony pike (Lepidosteus) ; 19. Finny pike (Polyp- terus) ; 20. Hollow-boned fiskes (Creloscolopes) ; 21. Solid boned fiskes (Pycnoscolopes) ; 22. Bald pike (Amia) ; 23. PrimEeval boned fiskes (Thrissopida) ; 24. Bony fiskca witk air passage to tke swimming bladder (Pkysostomi) ; 25. Bony fiskea witb- out air passage to tke swimming bladder (Physoclisti) ; 26. Unknown forms of transition between prima3val fiskes and ampkibious fiskes ; 27. Ceratodus ; 27a. Extinct Ceratodus from tke Trias ; 276. Living Australian Ceratodus ; 28. African ampkibious fiskes (Protopterus) and American ampkibious fiskes (Lopidosiren) ; 29. Unknown forms of transition between primse- val fiskes and ampkibia ; 30. Enamelled beads (Ganocepkala) ; 31. Labyrintk tootked (Labyrintkodonta) ; 32. Blind burrowers (Cseoilise) ; 33. Gilled ampkibia (Sozobranckia) ; 34. Tailed ampkibia (Sozura) ; 35. Frog ampkibia (Anura) ; 36. Dick- tkacantka (Proterosaurus) ; 37. Unknown forms of ti-ansition between Ampkibia and Protamnia; 38. Protamnia (common primary form of all Amnion animals) ; 39. Primary mam- mals (Promammalia) ; 40. PrimEeval reptiles (Proreptilia) ; 41. (Thecodontia) ; 42. Primseval dragons (Simosauria) ; 48. Ser- pent dragons (Plesiosauria) ; 44. Fisk dragons (Ickthyosauria) ; 45. Teleosauria (Ampkicoela) ; 46. Steneosauria (Opistkocoela) ; 47. Alligators and Crocodiles (Prostkocoela) ; 48. Carnivorous Dinosauria (Harpagosauria) ; 49. Herbivorous Dinosauria (Tkero- eauria); 60. Msestrickt lizards (Mosasauria) ; 51. Common primary form of Serpents (Opkidia) ; 52. Dog-tootkcd beaked lizards (Cynodontia) ; 53. Tootkless beaked lizards (Cryptodontia) ; 54. Long-tailed flying lizards (Rkampkorkyncki) ; 55. Skort-taUed APPENDIX. 399 flying lizards (Pterodactyli) ; 56. Land tortoises (Chersita) ; 67. Birds — ^reptiles (Tocornithes), transition form between reptiles and birds ; 68. Primaeval griffin (ArcheBopteryx) ; 59. Water beaked-animal (Omitliorhynelius); 60. Land beaked-animal (Echidna) ; 61. Unknown forms of transition between Cioa- cals and Marsupials ; 62. Unknown forms of transition between Marsupials and Placentals ; 63. Tuft Placentals (Villi- placentalia) ; 64. Girdle Placentals (Zonoplacentalia) ; 65. Disc Placentals (Discoplacentalia) ; 66. Man (Homo pithecogenes, by Linnaeus erroneously called, Homo sapiens.) Plate XV. (After page 369, Vol. II.) Eypothetical Sketch of the Monopliyletic Origin and tJie Diffusion of the Twelve Species of Men from Lemuria over the earth. The hypothesis here geographically sketched of course only claims an entirely provisional value, as in the present imperfect state of our anthropological knowledge it is simply intended to show how the distribution of the human species, from a single primaeval home, may be approximately indicated. The probable primasval home, or " Paradise," is here assumed to be Lemuria, a tropical continent at present lying below the level of the Indian Ocean, the former existence of which in the tertiary period seems very probable from numerous facts in animal and vegetable geography. (Compare vol. i. p. 361, and vol. ii. p. 315.) But it is also very possible that the hypothetical " cradle of the human race " lay further to the east (in Hindostan or Further India), or further to the west (in eastern Africa). Future investigations, especially in comparative anthropology and pateontology, wUl, it is to be hoped, enable us to determine the probable position of the primseval home of man more definitely than it is possible to do at present. If in opposition to our monophyletic hypothesis, the polyphyletic hypothesis — which maintains the origin of the different human species from several different species of anthropoid ape — be pre- ferred and adopted, then, from among the many possible hypo- theses which arise, the one deserving most confidence seems to bo 400 APPENDIX. that whicli assumes a double pitliecoid root for tlie Iniman race namely, an Asiatic and an African root. Foi' it is a very remark- able fact, that the African man-like apes (gorilla and chim- panzee) are characterized by a distinctly long-headed, or dolichocephalous, form of skull, like the human species peculiar to Africa (Hottentots, Caffres, Negroes, Nubians). On the other hand, the Asiatic man-like apes (especially the small and large orang), by their distinct, short-headed, or brachyccphalous, form of skull agree with human species especially characteristic of Asia (Mongols and Malays). Hence, one might be tempted to derive the latter (the Asiatic man-like apes and primreval men) from a common form of brachyccphalous ape, and the former (the African man-like apes and primoeval men) from a common dolichocephalous form of ape. In any case, tropical Africa and southern Asia (and between them Lemuria, which formerly connected them) are those portions of the earth which deserve the first consideration in the discussion as to the primsBval home of the human race ; America and Australia are, on the other hand, entirely excluded from it. Even Europe (which is in fact but a western peninsula of Asia) is scarcely of any importance in regard to the " Paradise question." It is self-evident that the migrations of the different human species from their primasval home, and their geographical distri- bution, could on our Plate XV. be indicated only in a very general way, and in the roughest lines. The numerous migrations of the many branches and tribes in all directions, as well as the very important re-migrations, had to be entirely disregarded. In order to make these latter in some degree cleai", our knowledge would, in the first place, need to be much more complete, and secondly, we should have to make use of an atlas with a number of plates showing the various migrations. Our Plate XV. claims no more than to indicate, in a very general way, the approximate geographical dispersion of the twelve human species as it existed in the fifteenth century (before the general diffusion of the Indo- Germanic race), and as it can be sketched out approximately, APPENDIX. 401 so as to harmonize with our hypothesis of descent. The geo- graphical barriers to diffusion (mountains, deserts, rivers, straits, etc.), have not been taken into consideration in this general sketch of m.igration, because, in earlier periods of the earth's history, they were quite different in size and form from what they are to-day. The gradual transmutation of catarrhine apes into pithecoid men probably took place in the tertiary period in the hypothetical Lemnria, and the boundaries and forms of the present continents and oceans must then have been completely different from what they are now. Moreover, the mighty in- fluence of the ice period is of great importance in the question of the migration and diffusion of the human species, although it as yet cannot be more accurately defined in. detail. I here, therefore, as in my other hypotheses of development, expressly guard myself against any dogmatic interpretation; they are nothing hut first attempts. 35 INDEX. Abtssinians, ii. 323, 330 AcalephsB, ii. 141 Acoelomi, ii. 148, 151 Aorania, ii. 196, 198, 200, 204 Aoyttaria, ii. 51, 62 Adaptation, i. 90, 156, 219 actual, i. 225, 231 correlative, i. 241 cumulative, i. 233 direct, i. 225, 231 divergent, i. 247 indirect, i. 224, 227 individual, i. 228 irregular, i. 229 monstrous, i. 229 potential, i. 224, 227 ■ — sexual, i. 230 universal, i. 231 unlimited, i. 249 Agassiz, Louis, i. 61 Agassiz's conception of the universe, i. 65 essay on classification, i. 61 history of creation, i. 63 history of development, i. 64 idea of species, i. 65 Albuminous bodies, i. 331 Algse, ii. 81, 82, 83 Alluvial system, ii. 15 Altaians, ii. 309, 317 Alternation of generations, i. 20G Americans, Ii. 309, 318. Amnion animals, ii. 204, 219 Amniota, ii. 204, 219 Amoabse, ii. 53, 279 Amoeboidea, ii. 53 Amphibia, ii. 209, 216 Amphioxua, ii. 198, 285 Amphirrhina, ii. 203, 205 Anamnionata, ii. 204 Animal Plants, ii. 144 Angiospermaj, ii. 83, 111 Annelida, ii. 133, 149, 151 Anorgana, i. 5, 328 Anorganology, i. 6 Anthozoa, ii. 143 Anthropocentrio conception of the universe, i. 38 Anthropoides, ii. 270, 275, 292 Anthropolithic period, ii. 15, 17 Anthropology, i. 7 Anthropomorphism, i. 18, 6G Ape-liko men, ii. 293, 300 Apes, ii. 241, 268, 270 Arabians, ii. 323, 330 Arachnida, ii. 180, 182 Archelminthes, ii. 148 Archezoa, ii. 132, 134 Arohigony, i. 183, 338 Archilithic period, ii. 8, 14 Arians, ii. 323, 331 Aristotle, i. 55, 76 Arthropoda, ii. 132 Articulata, ii. 119 Ascidia, ii. 162, 200 Ascones, ii. 141 Asterida, ii. 164, 166 Atavism, i. 207 Australians, ii. 308, 314 Autogeny, i. 339 Bae, Caul Erkst, i. 109 doctrine of filiation, i. 109 theory of development, i. 294 types of animals, i. 53 ; ii. 119 Basques, ii. 322 Bathybius, i. 184, 344 ; ii. 53 Batrachians, ii. 204 Bats, ii. 240, 261 Beaked mammals, ii. 233, 239 ■ reptiles, ii. 224, 226 Belief, i. 9 ; ii. 335 Berbers, ii. 323, 330 Biogenesis, fundamental law of, i. 309 ; ii. 33 INDEX. 403 Eiology, i. 6 Birds, ii. 204, 226 Braohiopoda, ii. 157 Brain, bladder of, in man, i. 304 development of, i. 303 Bruno Giordano, i. 22, 70 Bryozoa, ii. 160, 152 Buch, Leopold, i. 107 Biichner, Louis, i. 110 Buds, formation of, L 192 O Caffkes, ii. 312, 333 Calcispongiae, ii. 140, 144 Cambrian system, ii. 9, 15 Carbon, i. 330, 335 theory of, i. 335 Carboniferous system, ii. 11, 15 Carus Victor, i. 110 Catallacta, i. 51, 59 Catarrhini, ii. 270, 272 Caucasians, ii, 809, 321 Causa finalis, i. 34, 75 Causal eouception of the universe, i. 18, 74 Cells, i. 187, 346 formation of, i. 347 ■ theory of, i. 346 Cell-kernel, i. 188 membrane, i. 188 substance, i. 186 Csenolithic period, ii. 14, 16 Cephalopoda, ii. 160, 162 Chamisso, Adalbert, i. 206 Change of climate, i. 363 Chelophora, ii., 240, 257 Chinese, ii. 309, 317 Chorology, i. 351 Cloacal animals, ii. 234, 239 Cochlides, ii. 159, 160 Ccelenterata, ii. 136, 144 Coelomati, ii. 148, 151 Coniferas, ii. 82, 110 Constructive forces, L 90, 253, 337 Copernicus, i. 39 Corals, ii. 142, 144 Coreo-Japanese, ii. 309, 317 Cormophytes, ii. 80 Correlation of parts, i. 218 Cosmogeny, i. 321 Cosmological gas theory, i. 323 Crabs, ii. 174, 176 Craniota, ii. 198, 204 Creation, centres of, i, 352 the, i. 8 Creator, the, i. 64, 70 Cretaceous system, u. 12, 15 Crinoides, ii. 166, 171 CrocodUes, ii. 223, 224 Crustacea, ii. 173, 176 Cryptogamia, ii. 80, 82 Ctenophora, ii. 142, 144 Cultivated plants, i. 137 Curly-haired men, ii. 310, 333 Cuttles, ii. 160, 162 Cuvier, George, i. 50 Cuvier's dispute with Geoffroy, i. 88 history of creation, i. 59 palasontology, i. 54 idea of species, i. 50 ■ — theory of cataclysms, i. 58 theory of revolutions, i. 58 types of animals, i. 53 ; ii. 118 Cycadese, ii. 82, 110 Cyclostoma, ii. 202, 204 Cytod, i. 346 D Darwik Charles, i. 131 Darwinism, i. 149 Darwin's life, i. 132 travels, i. 132 theory of corals, i. 133 theory of selection, i. 150 study of pigeons, i. 141 Darwin, Ersismus, i. 118 Deoiduata, ii. 240, 255 Deduction, i. 85 ; ii. 357 Demooritus, i. 22 Devonian system, ii. 11, 14 Diatomea), ii. 51, 60 Diootylse, ii. 82, 112 Didelphia, ii. 239 Differentiation, i. 270, 283 Diluvial system, ii. 15 Dipneusta, ii. 204, 212 Divergence, i. 270 Division of labour, i. 247 Domestic animals, i. 137 Dragons, ii. 225 Dravidas, ii. 308, 319 Dualistic conception of the universe, i. 20, 75 Dysteleology, i. 15; ii. 353 404 INDEX. E EOHINIDA, ii. 1U6, 171 Encliinoderma, ii. 103, 166 Edentata, ii. 240, 251 Egg Animals, ii. 132, 134 Eggs, i. laO, 198 Egg of man, i. IDO, 207 ; ii. 279 Egg, cleavage of the, i. 190, 299 ; ii. 280 Egyptians, ii. 323, 330 Elephants, iL 257 Empiricism, i. 79 ; ii. 3i9 Eocene system, ii. 15, 16 Ethiopians, ii. 323, 330 Explanation of phenomena, i. 29 Feens, ii. 82, 101 Fibrous plants, ii. 82 Final cause, i. 22 Fins, ii. 309, 317 Fishes, ii. 206, 208 Flagellata, ii. 61, 57 Flat-nosed apes, ii. 270, 272 Flat worms, ii. 148, 150 Flint cells, ii. 51, 60 Flowering plants, ii. 82, 108 Flower animals, ii. 143 Flowerless plants, ii. SO, 82 Flying animals, ii. 240, 2G1 Freke, i. 119 Fulatians, 11. 308, 320 Fungi, ii. 82 G ■ Ganoid fish, ii. 208, 210 Gastraca, ii. 127, 128, 281 Gastrula, ii. 126, 127 Gegenbaur, i. 312; ii. 179, 193 Gemmation, i. 192 Generation, i. 209 Oeniis, i. 41 Geocentric conception of the uni- verse, i. 38 Geofi'roy S. Hilairc, i. 86, 116 Germans, ii. 323, 331 Germ buds, formation of, i. 193 ■ cells, formation of, i. 194 Gibbon, ii. 270, 275 Gilled insects, ii. 174, 176 Gill-ai'ches in man, i. 307 God, conception of, i. 70 Goethe, Wolfgang, i. 80 Goethe's conception of nature, i. 22 discovery of mid-jaw bone, i. 84 formative tendency L 91, 253 idea of God, i. 71 investigations in nature, i.81 materialism, i. 23 metamorphosis, i. 90 metamorphosis of plants, i. 82 philosophy of nature, i, 81 theory of development, i. 92 vertebra; of skull, i. 83 Genochoristus, i. 196 Gonochorism, i. 196 Gorilla, ii. 270 Grant, i. H§ Greeks, ii. 323, 331 Gregarinoe, ii. 133, 134 Gymnosperms, ii. 82, 109 H Halisacria, ii. 204, 214 Hare-rabbit, i. 148, 275 Heliozoa, ii. 64 Herbert, i. 119 Heredity, i. 176 Hermaphrodites, i. 196 Herschel's cosmogeny, i. 321 Holothuriaj, ii. 166, 172 Hoofed animals, ii. 249, 252 Hooker, i. 119 Hottentots, ii. 311, 333 Human races, ii. 296, 305, 308 soul, ii. 361 Huxley, i. 119, 145 ; ii. 208 Hybridism, i. 145, 210, 275 Hydromedusse, ii. 143, 145 Ice period, i. 307 ; ii. 17 Indecidua, ii. 241, 249 Individual development, Ii. 293 Indo-Chinese, ii. 309, 317 Indo-Germauic, ii. 323, 331 Induction, i. 85, ii. 357 Infusoria, ii. 132, 135 Inheritance, abridged, i. 212 INDEX, 405 Inheritance, acquired, i. 213 adapted, i. 213 amphigonous, i. 210 ooneervatiTe, i. 204 constituted, i. 216 contemporaneous, i. 217 - — continuous, i. 205 established, i. 216 homochronous, i. 217 Interrupted, i. 205 _ latent, i. 205 mixed, 1. 210 progiessive, i. 213 ■ sexual, i. 209 simplified, i. 212 • uninterrupted, 1. 205 — laws of, i. 20 i Inophyta, ii. 82, 93 Insects, ii. 184 Inseotivora, ii. 24:1, 259 Instinct, ii. 343 Invertebrata, ii. 118, 195 Iranians, ii. 323, 331 Japanese, ii. 309, 317 Jews, ii. 323, 330 Jura system, ii. 12, 14 Kant, Immantjel, i. 101, 321 Kant's Criticism of the faculty of judgment, i. 105 mechanisms, 1. 37, 102 philosophy of nature, i. 101 theory of descent, i. 103 theory of development, i. 321 theory of the formation of the universe, i. 101 Knowledge, a posteriori, i. 31 ; ii. 345 . a priori, i. 31 ; ii. 344 LABTRINTHULEa;, ii. 51 Lacertilia ii. 223 Lamarck] Jean, i. Ill Lamarck's anthropology, i. 115 ; ii. 264 philosophy of nature, i. 112 theory of descent, i. 113 Lamarckism, i. 150 LameUibranchia, ii. 158, 160 Lanoelet, ii. 198, 204, 285, Laplace's cosmogony, i. 321 Laurentian system, ii. 9, 14 Lemuria, i. 361, ii. 326 Leonardo da Vinci, i. 56 Leptocardia, ii. 196, 204 Leucones, ii. 141 LinniBus, Charles, i. 39 Linnaius' classification of animals, ii. 118 classification of plants ii. 78 designation of species, i. 41 history of creation, i. 44 system, i. 40 Lubbock, Sir John, ii. 298 Lyell, Charles, i. 126 Lyell's history of creation, i. 128 M Magyars, ii. 309, 316 Malays, ii. 308, 315 Malthus' theory of population, i. IGl Mammalia, ii. 231, 239 Man-apes, ii. 271, 27-5, 292 Marsupials, ii. 236, 239, 290 Matagenesis, i. 206 Materialism, i. 35 Matter, i. 22, ii. SCO Mechanical causes, i. 34, 74 Mechanical conception of the uni- verse, i. 17, 74 Mechanism, i. 37, 102 Mediterranese, ii. 308, 321 Medusas, ii. 143, 144 Mesolithic period, ii. 14, 20 Metamorphosis of the earth's strata, ii. 25 Metamorphosis, i 90 Migration, laws of, i. 373 of organisms, i. 354 of the human species, ii. 325 theory of, i. 367 Mind, i. 22; ii. 300 development of the, ii. 344, 360 Miocene period, ii. 15, 16 Miracles, i. 22 Molluscs, ii. 155, 160 Monera, i. 184, 343; ii. 52, 278 Mongols, ii. 308, 316 Monism, i. 34 4o6 INDEX. Monistic conception of the universe, i. 20, 74 MonocottyliE, ii. 82, 112 Monoglottonio, ii. 327, 333 Monogony, i. 183 Monophylites, il. ii Monophyletio hypothesis of descent, ii. 44 Monorrhina, ii. 203, 204 Monosporogonia, i. 194 Monotrema, ii. 234, 239 Morphology, i. 21 Morula, ii. 125, 127 Moses' history of creation, i 37 Moss animals, ii. 150, 162 Mosses, ii. 82, 97 Miiller, Fritz, i. 49, 73 ; ii. 174 Miiller, Johannes, i. 312 ; ii. 203 Muscinsi, ii. 82, 99 Mussels, ii. 159, 100 Myriapoda, ii. 182, 184 Myxomycetes, ii. 51, CO N Natural philosophy, i. 78 Negroes, ii. 309, 313, 333 Nemathelminthcs, ii. 149, 150 Newton, i. 25, 106 Non-amnionate, ii. 204, 209 Nubians, ii. 308, 320 O CEcoLOGT, ii, 354 Oken, Loreuz, i. 95 Oken's history of development, i. 293 philosophy of nature, i. 96 theory of infusoria, i. 97 protoplasm, i. 97 Olynthus, ii. 141 Ontogenesis, i. 293 Ontogeny, i. 10 ; ii. 33 Orang, ii. 271, 275 Organisms, i. 5, 328 Organs, i. 5 Origin of language, ii. 302, 327 Osseous fishes, ii. 208, 211 Ovularia, ii. 132, 134 Pachtoapdia, ii. 201 Palfeolithio period, ii. 11, 14 Palaeontology, 1. 54 Palissy, i. 66 Palm ferns, ii. 82, 110 Pander, Christian, i. 294 Papuans, ii. 310, 333 Paradise, ii'. 325 Parallelism of development, i. 313 Parthenogenesis, i. 197 Pedigree of amphibia, ii. 209 — anamnia, ii. 209 ■ apes, ii. 270 Perraean system, ii. 11, 14 Petrifactions, i. 64 Phanerogama, ii. 80, 82, 108 Philosophy, i. 79 ; ii. 350 Phylogeny, i. 10 ; ii. 33 Phylum, ii. 42 Physiology, i. 21 Pithecoid, theory, ii. 356 Placentalia, ii. 240, 244 Planula, ii. 126, 135, 281 Plana?a, ii. 125, 127 Planseada, ii. 280 Plasma, i. 185, 330 Plasmogony, i. 339 Plastids, i. 347 Plastids, theory of, i. 347 Platyelminthes, ii. 148, 150 Platyrrhini, ii. 270, 272 Pleistocene system, ii. 15 Pliocene system, ii. 15, 16 Polar man, ii. 30S, 317 Polyglottal, ii. 327, 333 Polynesians, ii, 308, 315 Polyphyletio theory of descent, ii. 45 Polyphylites, ii. 45, 303 Polyps, ii. 142 Polyp jellies, ii. 143, 144 Polysporogonia, i. 193 Population, number of, ii. 333 Porifera, ii. 139, 144 Primary mammals, ii. 239, 290 Primary period, ii. 11, 14 Primseval algae, ii. 82, 84 animals, ii. 131, 132 history of man, ii. 298 men, ii. 325 Primordial period, ii. 9, 14 Prochordata, ii. 278 Progenitors of man, ii. 279, 295 Progress, i. 277, 283 Promammalia, ii. 233, 239 Propagation, L 183 — amphigonic, i. 195 monogenic, i. 183 non-sexual, i. 183 INDEX. 407 Propagation, sexual, i, 195 — • virginal, i. 197 Protamnia, ii. 289, 295 Protamoebaj, ii. 52 Prothallophytcs, ii. 80, 97 Prothallus plants, ii. 80, 97 Protista, ii. 48 Protophyta, ii. 82, 85 Protoplasma, i. 185, 330 Protoplasts, ii. 51, 53 Protozoa, u. 121, 131, 132 Purpose in nature, i. 19 Purposelessness in nature, i. 20 E Eadiata, ii, 120 Eadiolaria, i. 333, 371 ; ii. 65 llapacious animals, ii. 210, 2G0 Eecent system, iL 15 Eeptiles, ii. 222, 224 Ehizopoda, ii. 51, CI Einged worms, ii. 149, 150 Eodentia, ii. '241, 257 Eomans, ii. 323, 331 Rotatoria, ii. 149, 150 Eotifera, ii. 150, 152 liound worms, ii. 149, 150 Eudimentary eyes, i. 13 gristle, i. 12 logs, i. 14 lungs, i. 289 mammary glands, i. 290 muscles, i. 12 nictitating membrane, i. 13 organs, i. 12 ■ pistils, i. 15 stamens, i, 15 tails, i. 289 teeth, i. 12 wings, i. 287 Sack wokms, ii. 283, 295 Sauria, ii. 222 Schaaffhausen, i. 110 Schleiclier, August, i. 108 ; ii. 301 Schleiden, J. M., i. 109 Science, i. 9 ; ii. 335 Scolecida, ii. 283, 295 Sea stars, ii. 1G4, ICG cucumbers, ii, IGG, 171 Sea dragons, ii. 20 1 lilies, ii. ICG, 177 nettles, ii. 141, 144 urchins, ii. 166, 171 Secondary period, ii. 14, 20 Selection assthetic, i. 2G8 artificial, i. 152, 170, 254 homochromic, i. 2G3 medical, i. 173 military, i. 171 musical, i. 267 natural, i. 1G8, 255 psychical, i. 269 sexual, i. 265 Spartan, i. 170 Self-division, i, 191 Semites, ii. 322, 330 Serpents ii. 223 Sexes, separation of, i. 241 Sexual characters, i, 209, 2G5 Silurian system, ii, 8, 14 Slavonians, ii, 323, 331 Snails, ii. 159, 160 Soul, the, i. 71, ii. 343, 3C2 Species, i. 41, 273, 301, 311 Specific development, i. 311 Spencer, Herbert, i, 119 ; ii. 307 Sperma, i. 197 Spiders, i. 180, 182 Spirobranchia, ii. 157, IGO Sponges, ii. 139, 144 Spores, formation of, i, 194 Stemmed plants, ii, 2S0 Straight-haired men, ii, 309, 314 Struggle for life, i. ICl, 252 Synamoeba, ii, 125, 280 Systematic development, i, 313 System of animals, ii, 132 apes, ii, 270 Arabians, ii, 330 arachnida, ii, 182 Arians, ii, 331 arthropoda, ii. 132 artioulata, ii. 177, 183 catarrhiui, ii, 270 coelenterata, ii. 144 Crustacea, ii, 176 didelphia, ii, 239 echinoderma, ii, 166 Egyptians, ii. 330 fishes, ii, 208 ■ formations, ii. 15 Germans, ii, 331 gilled Insects, ii. 177 4o8 INDEX. System of Grfeoo-Romans, ii. 331 Hamites, ii. 330 hoofed animals, ii. 252 human ancestors, ii. 295 human races, ii. 308 human species, ii. 308, 309 Indians, ii. 331 ■ Indo-Germani, ii. 331 insects, ii. 182 mammalia, ii. 239 mankind, ii. 295 marsupials, ii. 239 men and apes, ii. 271 molluscs, ii. 160 monodelphia, ii. 211 organisms, ii. 74, 75 placentalia, ii. 210 plants, ii. 82 platyrrhini, ii. 270 protista, ii, 51 reptiles, ii. 221: Semites, ii, 330 Slavonians, ii. 331 — spiders, ii. 182 star fishes, ii. 167 strata of the earth, ii. 15 tracheata, ii. 182 ungulata, ii. 252 vegetable kingdom, ii. 83 • vertebrata, ii. 201 •worms, ii. 150 zoophytes, ii. 144 T Tail of mah, i. 289, 308 Tangles, ii. 61, 82 Tartars, ii. 209, 317 • Teleology, i. 100, 291 Teleostei, ii. 208, 211 Teleological conception of the uni- verse, i. 20, 75 Tertiary period, ii. 14, 16 Thallophytes, ii. 80, 82 Thickness of the earth's crust, ii. 19 Thought, ii. 3G4 Thread plants, ii. 82, 93 Tocogony, i. 183 Tortoises, ii. 225 Tracheata, ii. 182 Transition forms, ii. 338 Transmutation, theory of, i. 4 Treviianus, i. 92 Trias system, ii. 12, 14 Tuft-haii-ed men, ii. 307, 309 Tunicata, ii. 152, 200 Turbellaria, ii. 283 Turks, ii. 309, 316 U linger, Franz, i. 109 TJngulata, ii. 249, 252 Unity in nature, i- 22, 338 Uralians, ii. 309, 317 Variability, i. 220 Variation, i. 219 Varieties, i. 276 Vertebrata, ii. 195, 205 Vital force, i. 22, 334 Vitalistic conception of the universe, i. 18 W Wagnee, Andreas, i. 138 Wagner, Moritz, i. 309 "Wallace, Alfred, i. 135 Wallace's chorology, i. 361 373 theory of selection, i. 136 Well's theory of selection, i. 150 Whales, ii. 210, 251 Will, freedom of the, i. 113, 237, 364 Wolff's theory of development, i. 293 Woolly-haired men, ii. 307, 309 Worms, ii. 117, 150 Z Zoophytes, ii. 130, 144 THE DESCENT OF MAN. Tlie Descent of Man, AND SELECTION IN EBLATION TO SEX. By Chakles Dar- win, M. A., F. K. S., etc. With Illustrations. New, revised aud enlarged edition. Complete in one vol. 12mo. Cloth. Price, j!3. OHgin of Species by Means of Natural Selection y Or, the Preservation of Favored Eaces in the Struggle for Life. Ncm and revised edition. By Cdaeles Daewin, M. A., F. E. S., F. G. Su, etc. With copious Index. 1 vol., 12mo. Cloth. Price, $2,00 ST. G-KORG-K MI"V".AJRT. On the Genesis of Species. By St. Gkoege Mivart, F. K. S. 12mo, S16 pages. IlkBtrutod. Cloth. Price, $1.75. SFKNCER. 2%e Principles of Biology. By Hekbert Spencee. 2 vols. $5.00. Man'>s Place in Nature. By Thomas H. Hoxlet, LL. D., F. E. S 1 vol., 12mo Clotii, Price, $1.25. On the Origin of Species. By Thomas H. Hoxlet, LL. D., F. R. S. lvoI.,12mo. Cloth. Price, 8L G-AXiTON", Hereditary Genius: An Inquiry into its Laws and Consequences. By Feanci) Galtoh New revised edition. 12mo. Cloth. Price, $2.00. iniG-XJIBJR. Primitive Man. Illustrated with thirty Scenes of Primitive Life, and 233 Figures of Objects belonging to Prehistoric Ages. By Lonis Figdiee, authoi of " The World before the Deluge," " The Ocean World," eto. I vol., 8vo. Cloth. Price, $4.00. Origin of Civilization, AND THE PRIMITIVE CONDITION OF MAN. By Sir Joan LnsBOCK, Bart., M. P. 1 vol., 12mo. Cloth. Price $2.00. Either of the above mailed to any address within the United States, on iwieipt of price. D. APPLETON & CO., Publishers, Nofl. 649 & B51 BROADWAY. N. T. THE GREAT ICE AGE, AND ITS RELATIONS TO THE ANTIQUITY OF MAN By JAMES GEIKIE, F. R. S. E. With Maps, Charts, and. numerous Illustrations. I vol., thick i2mo. . . . Price, $2.50. OPINIONS OF THE PRESS. *' Intelligent general readers, as well as students of geology, will find more infor- mation and reasonable speculation concerning the great glacial epoch of our globe in this volume than can be gathered from a score of other sources. The author writes not only for the benefit of his * fcUow-hammcrers/ but also for non-specialists, and any one gifted with curiosity in respect to the natural history- of the earth will be de- lighted with the clear statements and ample illustrations of Mr. Gcikic's * Great Ice Age.' " — Episcopal Register. " ' The Great Ice Age ' is a work of extraordinary interest and value. The subject is peculiarly attractive in the immensity of its scope, and exercises a fascination over the imagination so absorbing that it can scarcely find expression in words. It has all the charms of wonder-tales, and excites scientific and unscientific minds alike." — Boston Gazette. " Mr. Geikie has succeeded in writing one of the most charming volumes in the library of popularized science." — Uiica Herald. '* We cannot too heartily commend the style of this book, which is scientific and yet popular, and yet not so popular as to dispense with the necessity of the reader's putting his mind to work in order to follow out the author in his forcible yet lucid arguments. Nor can the attentive reader fail to leave the work with the same enthusiasm over the subject as is shown in every page by the talented a.uthoi."^PortlaKd Press. " Although Mr. Geikie's position in the scientific world is such as to indicate that he is a pretty safe teacher, some of his views are decidedly original, and he does not make a point of sticking to the beaten path." — Springfield Union. "Prof, Geikie's book is one that may well engage thoughtful students other than geologists, bearing as it does on the absorbing question of the unwritten history of our race. The closmg chapter of his "work, in which, reviewing his analytical method; he constructs the story of the checkered past of the last 200,000 years, can scarcely fail to give food for thought even to the indifferent." — Biiffalo Courier. " Every step in the process is traced with admirable perspicuity and fullness by Mr. Geikie," — Lo?idon Saturday Review. " It offers to the student of geology by far the completest account of the period yet published, and is characterized throughout by refreshing vigor of diction and originality of thought."— G^j;^^™^ Herald, D. APPLETON & CO., Publishers, 549 & 551 Broadway, N. Y. A thoughtful and valuable contribution to the best religious literature of the day. RELIGION AND SCIENCE. A Series of Sunday Lectures on the Relation of Natural and Revealed Religion, or the Truths revealed in Nature and Scripture. By JOSEPH LE CONTE, FB0FES30B 0¥ GEOLOGY AND MATUaAL HIBTOKY IK THE mOVEEBITY OF GALIFOENIA. l2mo, cloth. Price, $1.50. OPINIONS OF THE FMESS. " This work is chiefly remarkable as a conscientious effort to reconcile the revelations of Science with those of Scripture, and will be very use- ful to teachers of the different Sunday-schools." — Detroit Union. "It will be seen, by this resumS of the topics, that Prof. Le Conte grapples with some of the gravest questions which agitate the thinking world. He treats of them all with dignity and fairness, and in a man- ner so clear, persuasive, and eloquent, as to engage the undivided at- tention of the reader. We commend the book cordially to the regard of all who are interested in whatever pertains to the discussion of these grave questions, and especially to those who desire to examine closely the strong foundations on which the Christian faith is reared." — Boston youmal. " A reverent student of Nature and religion is the best-qualified man to instruct others in their harmony. The author at first intended his work for a Bible-class, but, as it grew under his hands, it seemed well to give it form in a neat volume. The lectures are from a decidedly re- ligious stand-point, and as such present a new method of treatment." — Philadelphia Age. " This volume is made up of lectures delivered to his pupils, and is written with much clearness of thought and unusual clearness of ex- pression, although the author's English is not always above reproach. It Is partly a treatise on natural theology and partly a defense of the Bible against the assaults of modern science. In the latter aspect the author's method is an eminently wise one. He accepts whatever sci- ence has proved, and he also accepts the divine origin of the Bible. Where the two seem to conflict he prefers to await the reconciliation, which is inevitable if both are true, rather than to waste time and words in inventing ingenious and doubtful theories to force them into seeming accord. Both as a theologian and a man of science, Prof. Le Cpnte's opinions are entitled to respectful attention, and there are few who will not recognize his book as a thoughtful and valuable contribution to the best religious literature of the day." — New York World. D. APPLETON & CO., Publishers, 549 & 551 Broadway, N. Y. A New Magazine for Students and Cultivated Readers. POPULAR SCIENCE MONTHLY, CONDUCTED BY Profeseor E. I-, YOUMANS. The growing importance of scientific knowledge to aU classes of thf" community calls for more efficient means of diffusing it. The Popular Science Monthly has been started to promote this object, and supplies a want met by no other periodical in the United States. It contains instructive and attractive articles, and abstract? of articles, original, selected, and illustrated, from the leading scientific men of differ- ent countries, giving the latest interpretations of natural phenomena, ex- plaining the applications of science to the practical arts, and to the opera- tions of domestic life. It is designed to give especial prominence to those branches of science which help to a better understanding of the nature of man ; to present the claims of scientific education ; and the bearings of science upon questions of society and government. How the various subjects of current opinion are affected by the advance of scientific inquiry will also be considered. In its literary character, this periodical aims to be popular, without be- ing superficial, and appeals to the intelligent reading-classes of the commu- nity. It seeks to procure authentic statements from men who know their subjects, and who will address the non-scientific public for purposes of ex- position and explanation. It will have contributions from Herbert Spencer, Professor Huxley, Professor Tyndall, Mr. Darwin, and other writers identified with specu- lative thought and scientific investigation. THE POPULAR SCIENCE MONTHLY is published in a large octavo, handsomely printed on clear type. Tenns, Five Dollars per annum, or Fifty Cents per copy. OPINIOKa OF THE PRESS. "Just the publication needed at the present day.** — Montreal Gazettz. ** It isi beyond comparison, the best attempt at joumalism of the kind ever made iu tlilo. country." — Home yournal. ** The initial number is admirably constituted.*' — Evening MaU. " In our opinion, the right idea has been happily hit iu the plan of this new monthly.*' .^Bujfalo Courier. ** A journal which promises to be of eminent value to the cause of popular education In this 'country." — N. V. Trib-une. IMPORTANT TO CLUBS. The PoptJLAR SaENCE Monthly will be supplied at reduced rates with any periodi- cal published in tliis country. Any person remitting Twenty Dollars for four yearly subscriptions will receive an ex- tra copy gratis, or five yearly subscriptions for $20. T he Po pular Science Monthly and Appletons' JoUftNAL (weekly), per annum, $8.oc J^p" Paytrtent, in all cases, must be in advance. Remittances should be made by postal money-order or check to the Fublishei3, D. APPLETON & CO.. 549 & 551 Broadway, New York.