: m'tttltti J* CORNELL UNIVERSITY LIBRARY ENGINEERING LiBRARY BOUGHT WITH THE INCOME OF THE SAGE ENDOWMENT FUND GIVEN IN 183I BY HENRY WILLIAMS SAGE BULLEN SiABRAM'S BOOKS 399 Madison Avenue New York City Cornell University Library QE 724.D27 1897 Relics of primeval life; beginning of lif 3 1924 004 626 648 The original of tliis book is in tlie Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924004626648 RELICS OF PRIMEVAL LIFE WORKS BY Sir J. William Dawson, LL.D., F.R.S., etc. Eden Lost and Won. Studies of the Earfy History and Final Destiny of Man, as tauglit in Nature and Revelation. i2mo, cloth $1.25 The work is in two parts. Part I. considers the physical and historical probabilities respecting the authorship and authority of the Mosaic books. Part II. treats of man and nature, fallen and restored. The Historical Deluge. Its relation to Scientific Discovery and to Present Questions, ismo, boards 25 " It is a very satisfactory statement. Will be very useful." — The New York Observer. The Meeting=Place of Geology and History. Illustrated. Lowell Lectures, 1894. x2mo. cloth 1.25 *'We commend these lectures heartily to all who are anxious to have a clear understanding of this im- portant discussion," — The Living Church. Modern Ideas of Evolution as related to Revela- tion and Science. Sixth Edition^ Revised and Mnlarsed. i2mOj cloth 1.50 ** Dr. Dawson is himself a man of eminent judicial temper, a widely read scholar, and a close, profound thinker, which makes the blow he deals the Evolution hypothesis all the heavier. We commend it to our readers as one of the most thorough and searching books on the subject yet published.''— TXe Christian at Work. The Chain of Life In Qeological Time, A sketch of the Origin and Succession of Animals and Plants. Illustrated. Third and Revised Edition, lamo, cloth 2.00 Egypt and Syria. Their Physical Features in Re- lation to Bible History. Second Edition^ Revised and Enlarged. With many Illustrations. " By-Paths of Bible Knowledee" Vol. VI. izmo, cloth 1.20 Fleming H. Revell Company New York : 112 Fifth Ave. Chicago : 63 Washington St. Toronto : 140 & 142 Yonge St. Cryptozoon Boreale, Dawson. Two divisions or branches of a large specimen collected by Mr. E. T. Chambers i the Ordovician of Lake St. John. {See Appendix D.) iFrontis, RELICS OF PRIMEVAL LIFE BEGINNING OF LIFE IN THE DAWN OF GEOLOGICAL TIME BY SIR J. WILLIAM DAWSON LL.D., F.R.S., Etc. lyiTH SIXTY-FIVE ILLUSTRATIONS ^ NEW YORK CHICAGO TORONTO FLEMING H. REVELL COMPANY 1897 CORNI-IJ UWiVfKCri Y UI,n;AI;Y The substance of a Course of Lectures on Pre-Cambrian Fossils, delivered in the Lowell Institute, Boston, in November, 1895 AUGUSTUS LOWELL Esq Vice-President of the Atnerican Academy of Arts and Sciences Trustee of the Lowell Institute AS THB WISB AND LIBERAL ADMINISTRATOR OF A NOBLB ENDOWMENT FOR THE ADVANCEMENT AND DIFFUSION OF KNOWLEDGE THIS WORK IS DEDICATED WITH MUCH RESPECT AND ESTEEM BY THE AUTHOR PREFACE TT IS now more than thirty-five years since the announcement was made of the discovery of remains supposed to indicate the existence of animal life in the oldest rocks known to geologists. It was hailed with enthusiasm by some as " opening a new era in geological science " ; but was regarded with scepticism by others, in consequence of the condition and mineral character of the supposed fossil, and be- cause of the great interval in time between the oldest animal remains previously known and these new claimants for recognition. Since that time, many new facts have been learned, and the question has been under almost continuous discussion and debate, with various fortunes, in different quarters. viii PREFACE The author was associated with the original discovery and description of these supposed earliest traces of life ; and has since, in the intervals of other work, devoted much time to further exploration and research, the results of which have been published from time to time in the form of scientiiic papers. He has also given attention to the later discoveries which have tended to fill up the gap between the Laurentian fossil and its oldest known successors. In 187s he endeavoured to sum up in a popular form what was then known, in a little volume named " The Dawn of Life," which has long been out of print ; and in 1893 the matter was referred to in a chapter of his work " Salient Points in the Science of the Earth." In 1 89s he was invited to present the subject to a large and intelligent audience in a course of lectures delivered in the Lowell Institute, Boston ; and the success which attended these lectures has induced him to reproduce them in the present work, in the hope that inquiries into the Dawn of Life may prove as fascinating to general readers as to those who prosecute them as a Preface ix "^ . matter of serious work, and that their presentation in this form may stimulate further research in a field which is destined in the coming years to add new and important domains to the knowledge of life in the early history of the earth. Hypotheses respecting the introduction and develop- ment of life are sufficiently plentiful ; but the most scientific method of dealing with such questions is that of searching carefully for the earliest remains of living beings which have been preserved to us in the rocky storehouses of the earth. There are many earnest labourers in this difficult field, and it will be the object of the writer in the following pages to do justice to their work as far as known to him, as well as to state his own results. J. W. D. CONTENTS I FACE The Chain of Life Traced Backward in Geological Time 3 II Life in the Early Cambrian 17 III Pre-Cambrian Life , . 47 IV f'oundations of the continents, and their general Testimony as to Life 79 V Probabilities as to Laurentian Life, and Conditions OF its Preservation 107 VI The History of a Discovery 125 VII The Dawn of Lif^ 147 XI! CONTENTS VIII Contemporaries of Eozoon i93 IX Difficulties and Objections 221 X The Origin of Life 245 XI Some General Conclusions 281 APPENDIX A. Geological Relations of Eozoon, etc. . B. Organic Remains and Hydrous Silicates C. Affinities of Eozoon, etc. D. Cryptozoon E. Receptaculites and Arch^eocyathus . F. Pre- Geological Evolution G. Controversies respecting Eozoon . H. Notes to Appendix, December, 1896 . 29s . 298 • 303 . 310 • 31S . 320 . 324 • .329 LIST OF ILLUSTRATIONS Cryptozoon Boreale , . . Fronliipiece Map .... . xvi I. Olenellus 20 2. Triarthrus . 23 3- Hymenocaris . 27 4- Ctenichnites . 32 5,6. Arch^ocyathus 35 7,8. Cryptozoon . 37,39 9- Fossils in Lower Cambrian Boulder 41 lo. Section Hanford Brook 51 II. Worm Tracks 53 12. Pre-Cambrian Fossils .... 54 13- Arenicolites and Aspidella 54 14. Cryptozoon 56 IS- Worm Burrows 67 16. Casts of Foraminifera 68 17- Tudor Eozoon 69 18. Laurentian America .... 85 19- Map of Grenville Limestones . 88 19A. Attitude of LimiTstone, C6te St. Pierri 91 20,21. Disturbed Beds 103 22. Section of Limestone .... 1 12 23- SiLICIFICATION of CORAL 113 24. Cast of Polystome lla IN Glauconite . 115 XIV LIST OF ILLUSTRATIONS FIG. PAGE 24A. Crinoid and Shell in Glauconite . . .116 25, Nature-print of Eozoon ..... 121 26, 27. Eozoon from Calumet ..... 130 28, 29. Canals of Eozoon 133 30, 31. Canals and Tubui.i 135 32. General Form of Eozoon 149 33,34. Eozoon WITH Funnels 152,153 35. Small Specimkn and Structure . . .155 36. Decalcified Eozoon 157 y]: Finest Tubuli filled with Dolomite . .158 38. Arrangement of Canals 159 39-41. Finest Tubuli 160-2 42. Canals after Mobius 163 43. Strom atocerium 172 44. Stromatopora 173 45. ccenostroma 174 46. Recent Protozoa 176 47. Fragment AL Eozoon 183 48,49. Nummulites and Calcarina . . . .186 50,51. ARCHiEOSPHERIN^ igo, 200 52. AcERVULiNE Eozoon 205 53, 54. Arch^ospherin/e 205, 208 55. Ditto, Finland 212 56. Eozoon Bavaricum 213 57. Arch^ozoon 215 58. Restoration of Eozoon 230 59. Eozoon in Different States .... 237 60. Nature-print of Large Specimen . To face 296 THE CHAIN OF LIFE TRACED BACKWARD IN GEOLOGICAL TIME GEOLOGICAL CHRONOLOGY OF LIFE. After Prof, C, A, White. Invertebrates. Vertebrates. Plants. Geological Systems OR Periods, ^ [ Tertiary Cretaceous . ^5 .S -S -o Ji S 9* -S 3 e .a S I g* 2 « IS W ^ S < ►5 Jurassic Permian 6 } Carboniferous Devonian Silurian Ordovician . Cambrian \ Etchemiiiian ^ Grenvilliau . Archajan ^L Note.— It is not supposed that the Geological Periods were of equal lengths as represented in the diagram. ' ERRATA. Where Cryptosoon prolificum occurs in the text, read Crypto- zoon proliferum. The line of " Phaenog-ams ■ in the table on opposite pag-e should be extended down to the Devonian Period. THE CHAIN OF LIFE TRACED BACKWARD IN GEOLOGICAL TIME T N infancy we have little conception of the per- ■*■ spective of time. To us the objects around us and even our seniors in age seem to have always been, and to have had no origin or childhood. It is only as we advance in knowledge and experience that we learn to recognise distinctions of age in beings older than ourselves. In thinking of this, it seems at first sight an anomaly, or at least contrary to analogy, that the oldest literature and philosophy deal so much with doctrines as to the origins of things. In this respect primitive men do not seem to have resembled children ; and the fact that our own sacred records begin with answers to such questions, and that these appear in the oldest literary renjains of so many ancient nations, and even in the folk-lore of barbarous tribes, might be used as an additional argument in favour of an early Divine revelation on such subjects, as a means RELICS OF PRIMEVAL LIFE of awakening primitive men to the comprehension of their own place in the universe. However this may be, it is certain that modern science at first took a different stand. The constancy of the motions of the heavenly bodies, our great time-keepers, and of the changes on the earth depending upon them, and the resolu- tion of apparent perturbations into cycles of greater or less length, impressed astronomers and physicists with the permanence of the arrangements of the heavens and their eternal circling round without any change. In like manner, on the rise of geology, the succession of changes recorded in the earth seemed interminable, and Hutton could say that in the geological chronology he could see " no vestige of a beginning, no prospect of an end." But the progress of investigation has changed all this, and has brought physical and natural science back to a position nearer to that of the old cosmo- gonies. Physical astronomy has shown that the constant emission of heat and light from the sun and other stars must have had a beginning, and is hurrying on toward an end, that the earth and its satellite the moon are receding from each other, and that even the spinning of our globe on its THE CHAIN OF LIFE TRACED BACKWARD j axis is diminishing in rapidity. In summing up these and other changes, Lord Kelvin says : " To hold the doctrine of the eternity of the universe would be to maintain a stupendous miracle, and one contrary to the fundamental laws of matter and force." So, on our earth itself, we can now assign to their relative ages those great mountain chains which have been emblems of eternity. We can transfer ourselves in imagination back to a time when man and his companion animals of to-day did not exist, when our continents and seas had not assumed their present forms, and even when the earth was an incandescent mass with all its volatile materials suspended in its atmosphere. It is true that in all the changes which our earth has undergone the same properties of matter and the same natural laws have prevailed ; but the interactions of these pro- perties and laws have been tending to continuous changes in definite directions, and not infrequently to accumulations of tension leading to paroxysmal vicissitudes. If all this is true of the earth itself, it is especially applicable to its living inhabitants. Successive dynasties of animals and plants have occupied RELICS OF PRIMEVAL LIFE the earth in the course of geological time; and as we go back in the record of the rocks, first man himself and, in succession, all the higher animals disappear, until at length in the oldest fossiliferous beds only a portion of the more humble inhabitants of the sea can be found. In the time of the forma- tion of the oldest of these rocks, or perhaps some- what earlier, must have been the first beginning of life on our planet. Just as we can trace every individual animal to a microscopic germ in which all its parts were potentially present, so we can trace species, genera, and larger groups of animals to their commencement at different points of the earth's history, and can •endeavour to follow the lines of creation or descent back to the first beings in which vital powers mani- fested themselves. All such beginnings must end in mystery, for as yet we do not know how either a germ or a perfect animal could originate from in- animate matter ; but we may hope at least to make some approximation to the date of the origin of life and to a knowledge of the conditions under which it began to exist, confining ourselves for the present principally to the Animal Kingdom. As preliminary to the consideration of this subject. THE CHAIN OF LIFE TRACED BACKWARD 7 we may shortly notice the grades of animals at present existing, and then the evidence which we have of their successive . appearance in different periods of geological time, in order that we may eliminate all those of more recent origin, in so far as the knowledge at present available will permit, and restrict our consideration to forms which seem to have been the earliest. In attempting this, we may use for reference the table of geological periods and animal types presented in the diagram facing this chapter, which is based on one prepared by Prof. Charles A. White, of the United States Geological Survey, with modifications to adapt it to our present purpose. In this table the leading groups of animals are represented by lines stretch- ing downward in the geological column of formations as far as they have yet been traced. Such a table, it must be observed, is always liable to the possibility of one or more of its lines being extended farther downward by new discoveries. The broadest general division of the Animal King- dom is into back-boned animals (Vertebrates) and those which have no back-bone or equivalent struc- ture (Invertebrates).' The former includes, besides ' The twofold primary division now sometimes used, into RELICS Of PRIMEVAL LIFE man himself, the familiar groups of Beasts, Birds, Reptiles, and Fishes. The latter consists of the great swarms of creatures included under the terms Insects, Crustaceans, Worms, Cuttle-fishes, Snails, Bivalve Mollusks, Star-fishes, Sea-urchins, Coral Animals, Sea - jellies. Sponges, and Animalcules. This mixed multitude of animals, mostly of low grade and aquatic, includes a vast variety of forms, which, though comparatively little known to ordinary observers, are vastly numerous, of great interest to naturalists, and, as we shall find, greatly older in geological date than the higher animals. It will be seen by a glance at the diagram that the higher vertebrates are of most recent origin, man himself coming in as one of the newest of all. Only the lower reptiles or batrachians and the fishes extend very far back in geological time. None of the other vertebrate groups reach, so far as yet known, farther back than the middle of the geological scale — probably in point of time very much less than this. Those of the invertebrates that breathe -air reach no farther back than the fishes, possibly not so far. On the other hand, all Metazoa and Protozoa, seems more arbitrary and unequal, and therefore of less practical value. THE CHAIN OF LIFE TRACED BACKWARD 9 the leading groups of marine invertebrates run with- out interruption back to the Lower Cambrian, and some of them still farther. Thus it would appear that for long ages before the introduction of land or air-breathing animals of any kind, the sea swarmed with animal life, which was almost as varied as that which now inhabits it. The reasons of this would seem to be that the better support given by the water makes less demands upon organs for me- chanical strength, that the water preserves a more uniform temperature than the air, and that arrange- ments for respiration in water are less elaborate than those necessary in air. Hence the conditions of life are, so to speak, easier in water than in air, more especially for creatures of simple structure and low vital energy. Besides this, the waters occupy two-thirds of the surface of the earth, and in earlier periods probably covered a still greater area. We are now in a position to understand that the Animal Kingdom had not one but many beginnings, its leading types arriving in succession throughout geological time. Thus the special beginning of any one line of life, or those of different lines, might form special subjects of inquiry ; but our present object is to inquire as to the first or earliest in- 10 RELICS OF PRIMEVAL LIFE troduction of life in our planet, and in what form or forms it appeared. We may, therefore, neglect all the vertebrate animals and the air-breathing invertebrates, and may restrict our inquiries to marine invertebrates. In relation to these, six of the larger divisions or provinces of the Animal Kingdom may suffice to include all the lower inhabitants of the ocean, whether now or in some of the oldest fossiliferous rocks. ^ Looking more in detail at our diagram, we observe that the higher vertebrates nearest to man in structure extend back but a little way, or, with a few minor exceptions, only as far as the begin- ning of the Kainozoic or Tertiary Period, in the later part of which we still exist. Other air-breathing vertebrates, the birds and the true reptiles, extend considerably farther, to the beginning of the previous or Mesozoic Period. The amphibians, or frog-like ' Some modern zoologists, having perhaps, like some of the old Greeks, lost the idea of the unity of nature, or at least that of one presiding divinity, prefer for the larger divisions of animals the term phylum or phylon, implying merely a stock, race or kind, without reference to a definite place in an ordered kosmos. THE CHAIN OF LIFE TRACED BACKWARD II reptiles, reach somewhat farther, and the fishes and the air-breathing arthropods farther still. On the other hand, our six great groups of marine invertebrates run back for a vast length of time, without any companions, to the lowest Palaeozoic, and this applies to their higher types, the cuttles and their allies, and the crustaceans, as well as to the lower tribes. Turning now again to our table, we find that these creatures extend in unbroken lines back to the Lower Cambrian, the oldest beds in which we find any considerable number of or- ganic remains, and leave all the other members of the Animal Kingdom far behind. If now we endeavour to arrange the leading groups of these persistent invertebrates under a few general names, we may use the following, begin- ning with those highest in rank : — (i) Insects and Crustaceans (ArthropODA). (2) Cuttles^ univalve and bivalve Shell-fishes (MOLLUSCA). (3) Worms (Annelida). (4) Sea - urchins and Sea - stats (ECHINODER- mata). (5) Coral Animals, Sea - anemones, and Sea- jellies (Ccelenterata). 12 RELICS OF PRIMEVAL LIFE (6) Sponges, Foraminifera and Animalcules of simple organization (PROTOZOA). There are, it is true, some animals allied to the moUusks and worms, which might be entitled to form separate groups, though of minor importance The position of the sponges is doubtful, and the great mass of Protozoa may admit of subdivision ; but for our present purpose these six great groups or provinces of the Animal Kingdom may be held to include all the humbler forms of aquatic life, and they keep company with each other as far as the Early Cambrian. If, in accordance with the pre- vious statements, we choose to divide the earth's history by the development of animal life rather than by rock formations, and to regard each period as presided over by dominant animal forms, we shall thus have an age of man, an age of mammals, an age of reptiles and birds, an age of amphibians and fishes, and an age of crustaceans and moUusks. It is only within recent years that the researches more especially of Barrande, Hicks, Lapworth, Linarrson, Brogger, and others in Europe, and of Matthew, Ford and Walcott in America, have enlarged the known animals of the Lower Cam- brian to nearly 200 species, and below this we THE CHAIN OF LIFE TRACED BACKWARD 1 3 know as yet very little of animal life. We may therefore take the Lower Cambrian, or "Olenellus Zone" as it has been called from one of its more important crustaceans/ as our starting-point for plunging into the depths below. In doing so, we may remark on the orderly and symmetrical nature of the chain of life, and on the strange fact that for so long ages animal life seems to have been confined to the waters, and to have undergone little development toward its higher forms. It is like a tree with a tall branchless stem bearing all its leaves and verdure at the top, or like some ob- scure tribe of men long living in isolation and unknown to fame, and then, under some hidden impulse or opportunity, becoming a great conquer- ing and dominant nation. Or to compare it with higher things, it is like the Christian religion, for ages confined to a small and comparatively un- important people, and developing slowly its faith and hopes, and then suddenly, under the personal influence of Christ and His apostles, spreading itself over the world, and in a few centuries becoming the ruling power in its greatest empire, surviving ' See figure, p. 20. 14 RELICS OF PRIMEVAL LIFE the fall of this and permeating all the great nations that sprang from its ruins. God's plans in nature, in history, and in grace seem to us very slow in their growth and maturity, but they are very sure. LIFE IN THE EARLY CAMBRIAN IS II LIFE IN THE EARLY CAMBRIAN T N the old Chaldean fable of the descent of Ish- tar into Hades, to recover her lost Tammuz, at each successive gate of the lower regions she is stripped of some of her ornaments and garments, till at length she has to appear naked and una- dorned in the presence of the lord of the Nether World. So in our descent from the surface on which men live, through the successive rocky layers of the earth's crust, we leave behind, one by one, all the higher forms of life with which we are familiar ; but there still remain to us our six groups of aquatic invertebrates, in the guise, it is true, of species and genera now unknown in a living state, yet well represented as far down as the lower part of the Cambrian. Let us now suppose that we take our stand on the shores of the Cambrian sea, or cast our dredge into its waters in search of " 2 1 8 RELICS OF PRIMEVAL LIFE these old animals ; though we can only actually do so by painfully hammering and chiselling them out of their rocky tombs, and this often in fragments which must be put together before we can fully realize the forms and structures of the animals to which they belonged. We may pause here, however, to remark that neither the geographical nor climatal conditions of the earth at this early time were similar to these with which we are now familiar. The marine animals of the Cambrian have left their remains in beds of sediment, which now constitute rocks forming parts of our continents remote from the sea, and much elevated above its level, showing that large areas, then under the ocean, are now dry land ; while there is no good evidence that the sea and land have changed places. The facts rather indicate that the continents have extended their area at the expense of the ocean, -which has, how- ever, probably increased in depth. In evidence of these statements, I need only mention that some of the oldest rocks in the Scottish and Welsh hills, in Scandinavia, in Russia and in Bohemia, are rich in Cambrian marine fossils. In America, in like man- ner, such rocks are found on the flanks of the Fig. I. — Oleiiellus Thompsonz, Hall. A characteristic Trilobite of tlic Lower Caiiilirian in North America. After VVrilcoU and spLciinen in Peter Kedpatli Museum. LIFE IN THli EARLY CAMBRIAN 21 Apalachians, in New Brunswick, and in Newfound- land, in the table-land of Colorado and in the Rocky Mountains. In point of fact, a map of the Northern Hemisphere at this period would show only a limited circumpolar continent with some outlying islands to the south of it, and shallows stretching across the northern part of the areas of the present Atlantic and Pacific Oceans. The great ocean, however, thus extending over most of the temperate and tropical parts of the North- ern Hemisphere, was probably also more muddy and shallow than that of modern times. The sur- face temperature of this vast ocean was also, it is probable, more uniform than that of the modern sea, while even its profounder depths or abysses would have more earth-heat than at present. Thus we may, without hesitation, affirm that in this early age the conditions for the introduction of swarming marine life of low grade, and its extension over the whole earth, were at a maximum. Let us inquire, then, what these old Cambrian seas actually produced, more especially in the early portions of that ancient and probably protracted time. The most highly organized type of which we 22 RELICS OF PRIMEVAL LIFE have any certain evidence is that of the Crustacea, the group to which our modern lobsters and crabs belong, and its most prominent representatives are the trilobites (Figs, i, 2), so called from the three lobes into which the body is divided. These creatures are indeed remarkable for the twofold property of bilateral Symmetry, and fore and aft jointed structure, both based on the number three. From front to rear we have a large head, usually with well-devel- oped eyes and oral organs, a middle or thoracic part composed of a series of movable segments, and a tail-piece sometimes small, sometimes nearly as large as the head. Transversely, the body is divided into a central and two lateral lobes, which can be seen in the head, the thorax, and usually in the tail as well. The organization of these animals must have been as complex as that- of most existing Crustaceans. Their nerve system must have been well developed ; a vast number of muscles were required to move the different parts of the trunk, and the numerous and complex limbs which have been observed in some of the species, and no doubt were possessed by all. Their digestive and circu- latory organs must have been in proportion to the complexity of their locomotive organs. Figure 2, Fig. 2. — Triarth7-us Becki^ Green. A Trilobite of primitive type, showing its limbs and antennae. (After Beecher.) LIFE IN THE EARLY CAMBRIAN ^5 borrowed from Beecher,* shows the limbs of a species, not of the Lower Cambrian, but of a some- what later formation. There can be no doubt, how- ever, that those of earlier species were equally per- fect, more especially as Triarthrus is an animal of an old type approaching to extinction in the age suc- ceeding the Cambrian, and its representatives in the earlier and palmy days of the family could not have been inferior in organization. These creatures swarmed in every sea in the Cambrian period, and were represented by a great number of spe- cies, some of them of large size, others very small ; some many - jointed, others few - jointed, and with a great variety of tubercles, spines, and other orna- mental and protective parts. If we ask for their affinities and place "in the great group of Crustacea, the answer must be that, while in some points allied to the higher forms, they approach most nearly to those which occupy a medium position in the class, and are, in fact, a composite type, presenting points of structure now distributed among different groups. If we ask for affinities with lower groups, we have to reply that their nearest allies in this direction are ' American Journal of Science, i8g6. 26 Relics of primeval life the bristle - footed marine worms ; but there is a vast gap, both in the Cambrian and Modern seas, between any of these worms and the Crustacea, which, either as embryos or as adults, have any re- semblance to them. The Trilobites, after appearing in a great variety of generic and specific forms, and playing a most important part in their time, were not destined to continue beyond the Carboniferous period, and be- fore that time they were beginning to give place to the Limuli, King-crabs, or Horseshoe-crabs, a few species of which continue on our coasts until the present time. In this limited duration the Trilobites present a strange contrast to certain shrimp - like Crustaceans, their contemporaries (the Phyllopods), which very closely resemble some still extant, and the same remark applies to swarms of little bivalve Crustaceans (Ostracods), which are still represented by hosts of modern species both in the sea and in the fresh waters. There is, however, a remarkable group of shrimp-like Crustaceans, represented in the modern world by only a few small species, which in the Cambrian age attained greater size, and consti- tute a very generalized type combining characters now found in lower and higher groups of Crustacea. LIFE IN THE EARLY CAMBRIAN 2^ Hymenocaris vermicauda of Salter (Fig. 3) may serve to illustrate one of these primitive forms. In point of fact, as Dr. Henry Woodward has shown in an able presidential address delivered to the Geological Society in 1895, at the base of the Lower Cambrian we still have several distinct groups of Crustacea ; and if with some we were to hold them Fig. 3. — Hymenocaris vermicauda, Salter. A Lower Caiiibrian Shrimp of generalized type. (After Salter.) as traceable to one original form or to a worm-like ancestor, we must seek for this far back in those pre-Cambrian rocks in which we find no Crustaceans whatever. There is, it is true, no good reason to demand this ; for whatever the cause, secondary or final, which produced any form of Crustacean in the Lower Cambrian, it might just as well have pro- duced several distinct forms. Evolutionists seem 28 RELICS OF PRIMEVAL LIFE to be somewhat unreasonable in demands of this kind, for any cause capable of originating a new form of living being, might have been operative at the same time in different localities and under some- what diverse conditions, and may also have acted at different times. All imaginary lines of descent of animals are more or less subject to this con- tingency ; and this may partly account for the great diversity in the lines of aiifiliation presented to us by evolutionists, which may in part have a basis in fact in so far as distinct varietal and racial forms are concerned, but may just as likely be entirely fallacious in the case of true species. In any case, in the lowest rocks into which we can trace Crustacea, we have already probably five of the orders into which their successors in the modern seas are divided by zoologists ; and this is certainly a singular and suggestive fact, the significance of which we shall be better prepared to understand at a later stage of our investigation. Allied in some respects to the Crustacea, though much lower in grade, are the marine Worms — a great and varied host — usually inhabiting the shal- lower parts of the ocean ; though the 330 species collected by the Challenger expedition show that LIFE IN THE EARLY CAMBRIAN 29 they also abound in those greater depths to which voyagers have only recently had access. Sea-worms seem thus to be able to live in all depths, as well as in all climates ; and in accordance with this they abound in the oldest rocks, which are often riddled with the holes caused by their burrowing, or abundantly marked on the surfaces of the beds with their trails. The great province of the Mollusca, in which, for our present purpose, we may include some aberrant and rudimentary Molluscoids, is now best known to us by its medium types, the univalve and bivalve Shell-fishes ; the higher group of the Cuttle- fishes and Nautili, though not uncommon, being much less numerous, and one at least of the lower groups, the Lamp-shells or Brachiopods, being repre- sented in the modern world by but few forms. The extension of the Mollusks backwards into the Cam- brian is remarkable as being on the whole meagre in comparison Ill PRE-CAMBRIAN LIFE T T AVING traced the chain of life through the long geological ages, from the present day back to the Cambrian Period, we may now take our stand on the fauna of the lowest Cambrian or Olenellus Zone, as a platform whence we may dive into still deeper abysses of past time. Here, however, we seem to have arrived at a limit beyond which few remains of living things have yet been discovered, though there still remain pre-Cambrian deposits of vast thickness and occupying large areas of our continents. These pre-Cambrian formations are as yet among those least known to geologists. The absence of fossils, the disturbances and alter- ations which the rocks themselves have undergone, and which make their relative ages and arrangement difficult to unravel, have acted as deterrents to amateur geologists, and have to some extent baffled the efforts of official explorers. In addition to this, workers in different regions have adopted different 47 48 RELICS OF PRIMEVAL LIFE methods of arrangement and nomenclature ; and in a very recent address, the Director-General of the Geological Survey of Great Britain expresses his inability to satisfy himself of the equivalency of the different pre-Cambrian groups on the opposite sides of the Atlantic, and in consequence prefers to retain for those of Britain merely local names. On the other hand, those who hold the modern theories of gradual evolution repudiate the idea that the Lower Cambrian fauna can be primitive, and demand a vast series of changes in previous time to prepare the way for it. In any case this com- paratively unexplored portion of geological time holds out the inducement of mystery and the possi- bility of great discoveries to the hardy adventurers who may enter into it. It must now be our effort to explore this dim and mysterious dawn of life, and to ascertain what forms, if any, are visible amid its fogs and mists. The Kewenian or Etcheminian. In certain basal Cambrian or infra - Cambrian beds, found by Matthew in Southern New Bruns- wick, by Walcott in Colorado, and by Scandinavian and English geologists in their respective countries, PRE-CAMBRIAN LIFE 49 we find a few remains referred to Algae, or seaweeds ; small tests or shells of Protozoa ; burrows and trails similar to those of modern sea-worms ; a few bivalve shells allied to modern Lingulae, but presenting some remarkable generalized characters ; some bivalve and shrimp-like Crustaceans, spicules of sponges, and large laminated forms (Cryptozoon) similar to those already referred to as occurring in the Upper Cambrian ; also certain mysterious markings that are supposed to have been produced by the arms or tentacles of free-swimming animals of various kinds. In these lower beds the Trilobites have nearly or quite disappeared, being represented only by doubtful fragments. The beds of rock, origin- ally sandy or muddy sediments, contain fossils very sparingly, and only in certain layers separated by great thicknesses of barren material, as if earthy matters were being deposited very rapidly, or as if animal life was rare on the sea-bottom except at intervals. It has, however, been suggested as possible ^ that much of the marine population in those early times consisted of pelagic or swimming animals destitute of any hard parts that could be • By Prof. Brookes, of Johns Hopkins University. 4 so RELICS OF PRIMEVAL LIFE preserved. In addition to biological arguments in favour of this view, there is the fact that some of the beds are stained with carbonaceous or coaly matter, as if the sediment had been mixed with decomposed remains of plants or animals retaining no determinate forms. Future discoveries may in- crease our knowledge of the life of this period preceding the Cambrian, but it is evident that so far as these rocks have been examined, they indicate a great step downward in regard to the variety and complexity of marine life. Still we must bear in mind that in later periods there have been times of rapid deposition, in which, in certain localities at least, great thicknesses of rock with few organic remains were formed. We have instances of this in the later Cambrian, in the Ordovician, and still later in the Permian and Trias. Thus in the beds immediately underlying the lowest Cambrian we may be passing through a tract of comparative barrenness to find more fertile ground below. It is also to be observed that there is evidence of disturbance occurring in the interval between the lowest Cambrian and the highest pre-Cambrian, which may involve the lapse of much time not PRE-CAMBRIAN LIFE SI recorded in the localities hitherto explored, but of which monu- ments may be found elsewhere. We may now, taking some North American localities as our best available guides, inquire as to the nature and contents of the beds next below the Lower Cambrian. In Southern New Brunswick, Matthew indicated, several years ago, the occurrence of certain con- glomerates and sandy and slaty beds over the rocks, mostly of igneous origin, constituting a great thickness of beds under the Cam- brian, and known locally as the " Coldbrook " series, which is pro- bably equivalent to the Huronian of Northern and Western Canada, to be noticed later. These beds were at first regarded as an upper member of the Huronian, but sub- sequently it was thought better to unite them with the overlying Cambrian as basal Cambrian. Cr^ e VO 7 K S? W- 52 RELICS OF PRIMEVAL LIFE The fact that these problematical beds were ascer- tained to be unconformable to the Cambrian, and the peculiarity of their fossils, led to their being con- stituted a separate group under the name Etche- minian, which seems to represent a time and conditions introductory to the Cambrian (Fig. lo). The fossils in these beds are few and hard to find. Matthew has kindly furnished me with the following list* The Trilobites are conspicuous by their absence. Sea- worms have left burrows, trails, and casts, which probably represent several species (Fig. 1 1). A single little shell (Volborthella) is supposed to be a pre- cursor of the straight chambered shells allied to the modern nautilus, which become so large and numer- ous in succeeding periods. There are a few univalve shell-fishes allied to modern sea-snails, a brachiopod of the antique genus Obolus, some fragments sup- posed to represent Cystideans, a rudimentary type of the stalked sea-stars so abundant later, spicules of sponges and minute Protozoa, with shells not unlike those of their modern successors. This meagre list sums up the forms of life known in the Etcheminian of this district, one in which the Cambrian beds ' " Transactions Royal Society of Canada," voL vii. t-kE^dAMBRtAi* LIFE 55 Fig. II. — Trails of Worms of two types (Psammchnites and Planilites). exhibit the rich and varied fauna of Trilobites and other animals described and figured by Matthew in several successive volumes of the "Transactions of the Royal Society of Canada " (Fig. 12). Beds in Newfoundland (the Signal Hill and Random Sound series), underlying the Lower Cambrian, have afforded to , Murray and Billings some well - characterized worm-castings of spiral form, and a few problematical forms known as Aspidella, which may be Crustaceans or Mollusks allied to the limpets (Fig. 13). In a thick series of pre-Cambrian beds in the Fig. 12. — Group of pre- Cambrian (Etcheminian) Animals from (he Etcheminian. (After Matthew. ) The name " Etcheminian " is derived from that of an ancient Indian tribe of New Brunswick. (a) Volborthella, supposed to be a Cephalopod shell. (3) Pelagiella. fc) Ortho- theca, supposed to be Pteropods. {d) Primitia, an Ostracod Crustacean, [e] Obolus, a Brachiopod shell. (y) Platysolenites, probably fragment of a Cystidcaii. [g) Globigerinae, casts of Foraminifeial shells, Etcheminian, New Brunswick. Fig. \%.^Arentcoliies {Spiroscolex) spiraies (Billings) and Aspideila tenanovica (Billings), Signal Hill Series, Nezvfoundland, Fig. 14. — Fragment of Crypt ozoon J Grand Caiiony Arizona. Photograph from a specimen presented by Dr. Walcott to the Peter Redpath Museum. fRE-CAMBRIAN LIFE 57 Colorado Canon in the Western United States, Walcott has found a small roundish shell of uncer- tain affinities,* a species of Hyolithes, probably a swimming sea-snail or Pteropod, a small fragment which may possibly have belonged to a Trilobite, and some laminated forms which, if organic, are related to the Cryptozoon already mentioned (Fig. 14). The Kewenian series of Lake Superior has yielded no fossils, but the pipestone beds of Minne- sota, supposed to be about the same age, have afforded a small bivalve shell allied to Lingula ; ^ and the black shales of the head of Lake Superior contain some impressions supposed to be trails of animals.' It has been a question whether the beds above referred to should be regarded as a downward con- tinuation of the Cambrian, or as the upper part of an older system. Matthew, whose opinion on such a subject is of the highest authority, regards them as a distinct system, but as belonging, with the Cambrian, to the great Palaeozoic Period. Van ' Discinoid or Patelloid. " Winchell. ' Selwyn and Matthew. 58 RELICS OF PRIMEVAL LIFE Hise, and some other United States authorities, would separate them even from the Palaeozoic, and unite them with the underlying Huronian, as re- presenting a " Proterozoic " or " Algonkian " Period. This is merely a matter of classification, necessarily more or less arbitrary ; but I believe the facts to be stated subsequently show that it will be best to unite the Etcheminian and its equivalents with the Palaeozoic, and to place the groups lower than this in one great division, equivalent to Palaeozoic, and for which many years ago I proposed the name " Eozoic," or that of the Dawn of Life. Having thus hastily glanced at the slender fauna of the rocks immediately below the Cambrian, we may now proceed to inquire a little more in detail into its true value and import as leading toward the beginning of life. I have -already referred to the apparently sudden drop in the number of groups and of species below the base of the Cambrian, and have hinted that this may be an eifect of temporary local conditions of deposit or of defective information. Another fact that strikes us is the diverse and mis- cellaneous character of the fossils that remain to us ; and this would suggest that we are either dealing with a mere handful picked at random, as it were. PRE-CAMBRIAN LIFE 59 out of a richer fauna, or that in the beginning of things the gaps and missing links between different forms of life were even more pronounced than at present. This, however, would be likely to occur if the plan of creation was to represent at first different types, with few forms in each ; to produce, in short, a sort of type collection representing the whole range of organization by a few characteristic things rather than to give a complete series, with all the intermediate connections. Such a mode of introduction of life is not d priori improbable, how- ever at variance with some prevalent hypotheses. Beginning with the higher Invertebrates, we must not conclude that we have altogether lost the Trilo- bites. The fragments referred to this group may represent at least a few species, and it would be very interesting to know more of these as to their relations to their successors, and whether they are tending to lower or more embryonic forms. The bivalve Crustaceans (Ostracods) may be regarded as inferior in rank to the Trilobites, but are still very complex, and specialized animals and a specimen silicified in such a manner as to show the interior organs testified that, as far back as the Carboniferous at least, these creatures were as highly organized as 6o RELldS OF PRIMEVAL LIFE at present,' while their generally larger size in the earlier formations tends to show that they have rather been degenerating in the lapse of geological time. In regard to the Sea-worms, the burrows, cast- ings, and trails found in the pre-Cambrian beds are scarcely, if at all, different from those now seen on sandy and muddy shores, and would seem to indicate that these highly organized and very sensitive and active creatures swarmed in the muddy bottom of the pre-Cambrian Sea, and lived in the same way as at present. It is impossible, however, to know anything of the internal structures of these creatures, but the marks left by their bristle-bearing feet seem to indicate that some of them at least belong to the higher group of Sea-centipedes, creatures rival- ling the Crustaceans in complexity of organization, and near to them in plan of structure, though at present usually widely separated from them in cur- rent systems of classification. In the Ordovician system, next above the Cambrian, Hinde has found many curiously formed jaws of animals of this kind, ' PalcEocypris Edwardsi, Brougniart, Coal Formation of St. Etienne, France. PRE-dAlViBRiAN LIFE 6t which show at least that their alimentary arrange- ments were similar to those now in force. If any of the problematical " Conodonts " discovered by Pander in the Cambrian of Russia belonged to marine worms, this inference would be extended back to the Lower Cambrian, so that if the evidence of structure anywhere remains we may hope to find that the pre-Cambrian worms were not inferior to their more modern successors, perhaps even that in this early period, when they probably played a more important part in nature, they were of higher organization than in later times. The evidence as to pre-Cambrian mollusks, so far as it goes, is even more curious. The little shell called Volborthella, so far as can be judged from its form and internal structure, is a miniature repre- sentative of these straight Nautili, the Orthoceratites of the Ordovician and later Palaeozoic rocks ; and no one doubts that these latter belong to the highest class of the Mollusks, a class approaching in the development of nerve system and sensory organs to the Vertebrates themselves. This tiny member of the great class of Cuttle-fishes may perhaps have been more nearly allied to the modern Spirula than to the Nautilus. In any case, if, as seems altogether 62 RELICS O^ PRIMEVAL Ltj'fi probable it was, a mollusk, it must have been one of advanced type, and with a highly complex struc- ture, as well as the singular apparatus for flotation implied in a chambered shell with a siphuncle. Next to this among these primitive Mollusks are straight and spiral shells representing those delicate and beautiful animals of the modern seas, the Pteropods, or wing-footed Sea-snails, beautiful and graceful creatures, the butterflies of the sea, and moving in the water with the greatest ease and beauty by the aid of membranous fins, or wings, sometimes brightly coloured. These creatures abound in all latitudes in the modern ocean, and their delicate shells sometimes accumulate in beds of " Pteropod sand." They very early entered on the arena of marine life, and have continued to this day. We miss here the two great Molluscan groups of the creeping Sea-snails like the limpet and whelk, and of the ordinary bivalves like the oyster and cockle. Both are present in the lowest Cambrian, though in small numbers compared with their present abundance. Possibly they had not yet ap- peared in the Etcheminian Sea, though the muddy and sandy bottoms, evidenced by its slates and PRE-CAMBRIAN LIFE 63 sandstones, would seem to have afforded favourable habitats, and warrant the expectation that species may yet be found. The case was different with the little group of the Lamp-shells, or Brachiopods. These creatures, somewhat resembling the ordinary bivalves in their shelly coverings, were very dissimilar in their in- ternal structure, and once settled on the bottom they were attached for life, not having even the limited means of locomotion possessed by the Sea-snails and common bivalves. They collected their food wholly by means of currents of water produced by cilia, or movable threads, on arms ,or processes within their shells. In this they resehibled the young or embryo stages of some of the more ordin- ary Mollusks, though they are so remote from these in their adult condition that they have usually been placed in a distinct class, and some naturalists have thought it best to separate them from the Mollusks altogether. Their history is peculiar. Coming into existence at a very early date, they became very abundant in early Palaeozoic times, then gradually gave place to the ordinary bivalves, and in the modern seas are represented by very few species. Yet while in the middle period of their history they 64 RELICS OF PRIMEVAL LIFE are represented by very many peculiar specific and generic forms. Some of the earliest types, like Obolus and Lingula, persist very long, and the latter has continued without change from the Early Cam- brian to the Modern period. The great group of the Sea-stars and Sea-urchins appears only in a few of its lower forms, and seems to be the only class represented by embryonic types. The coral animals are absent, so far as known. The Jelly-fishes and their allies cannot be preserved as fossils, but some peculiar markings, at one time regarded as plants, are now supposed to be trails made by the tentacles of creatures of this kind moving over muddy bottoms. A few spicules in- dicate Sponges, and the ubiquitous groups of the marine Protozoa, the Foraminifera and the Radio- launus, are represented by shells scarcely distinguish- able from those of modern species. The great and peculiar forms represented at this early time by Cryptozoon and its allies seem long ago to have perished, and we shall have to return to them in a later stage of our inquiry. To sum up the little that we know of this earliest Palaeozoic life : — It was perfect of its kind, equally pregnant with evidences of design, and of PRE-CAMBRIAN LIFE 65 the nicest and most delicate contrivance as the animal life of any later time, and it presupposed vegetable life and multitudes of minute organic beings altogether unknown to us to nourish the creatures we do know. As an example of this, a little Brachiopod or sponge nourished by the cur- rents produced by its cilia, or a Jelly-fish gathering food by its thread-like tentacles, or a Globigerina selecting its nourishment by its delicate gelatinous pseudopods, required an ocean swarming with minute forms of life, which probably can never be known to us, but every one of which must have been an in- scrutable miracle of organization and vital function. Lastly, with reference to our present subject, the Etcheminian fossils carry life backward one whole great period earlier than the Lower Cambrian, and appear to indicate that we are approaching a begin- ning of living things in the Palaeozoic world. Much no doubt remains to be discovered, but it would seem that any future discoveries must fail to negative this conclusion. The Huronian, In whatever way the rocks immediately below the Cambrian may be classified, it is certain that S 66 RELICS OF PRIMEVAL LIFE the next system in descending order is that to which Logan long ago gave the name Huronian, from its development on Lake Huron ^—a. name to which it is still entitled, though there may, perhaps, be some grounds for dividing it into an upper and lower member.* To this sub-division, however, we need not for the present give any special attention. In the typical area of Lake Huron the Huronian consists of quartzites, which are merely hardened sandstones, of slates which are muddy or volcanic-ash beds, of conglomerates or pebble-rocks, and of coarse earthy limestone. With these rocks are deposits of igneous material which represent contemporary volcanic eruptions. In other districts, as in New Brunswick, Newfoundland, etc., the beds have been considerably altered, and are locally more mixed with igneous products. The physical picture pre- ' Dr. G. M. Dawson, F.R.S., the present Director of the Geo- logical Survey of Canada, whose judgment in this matter should be of the highest value, holds that the original simple arrange- ment of Logan still holds, notwithstanding the multitude of new names proposed by the Western Geologists of the United States. " Van Hise, " Pre-Cambrian Rocks of North America." Comptes Rendus, 5th Session International Geol. Congress 1891, p. 1^4. Also "Report U.S. Geol. Survey, 1895." PRE-CAMBRIAN LIFE 67 sented to us by the Huronian is that of a shore deposit, formed under circumstances in which beds of pebbles and sand were intermixed with the pro- ducts of neighbouring volcanoes. Such a formation is not likely to afford fossils in any considerable number and variety, even if deposited at a time of Fig. 15. — Annelid Burrows, Hastings Series, Madoc, X. Transverse section 0/ Worm-hurrow — magnified, as a transparent object, (a) Calcareo-siiicious rock, ifi) Space filled with calcareous spar, (f) Sand agglut- inated and stained black, (jl) Sand less agglutinated and uncoloured. s. Trans- verse section 0/ Worm-burrow on weathered sur/acet natural size. 3. The same, magnified. abundant marine life. It is therefore not wonderful that we find little evidence of living beings in the Huronian. In Canada I can point to nothing of this kind, except a few cylindrical burrows, pro- bably of worms (Fig. 15), and spicules possibly of silicious sponges, which occur in nodules of chert in the limestones, traces of laminated forms like 68 RELICS OF PRIMEVAL LIFE Cryptozoon or Eozoon (Fig. 17), and minute car- bonaceous fragments which may be debris of sea- weeds or Zoophytes. In rocks of similar age in the United States, Gresley has recently discovered worm-burrows, and in Brittany there are quartzite beds in which Barrois and Cayeux believe that Fig. 16. — Casts of Foraminifera, from the Huronian of Brittany. (After Cayeux.) Compare with Globigerinae on Fig. 12 and Archasospherinae, Figs. 50-54. they have found tests of Radiolarians, Foraminifera and spicules of sponges, but their organic nature has been denied by Rauff, of Bonn. The casts of Fora- minifera, however, at least appear to be organic (Fig. 16), and it is quite likely that Cayeux may be Fig. 17. — Cryptozoon or Eozoon from the Hastings Series, Tudor, Ontario (natural size). From a specimen collected by the late Mr. Vennor, and now in the collection of the Geological Survey, Ottawa. (See also Frontispiece and iigure oi Eozoon Bavari- cum, p. 313.) PRE-CAMBRIAN LIFE 7 1 able to verify his Radiolarians and sponges as well. Matthew's observations in New Brunswick in any case establish their probability. Giimbel also re- cognises a species of Eozoon in the equivalent rocks of Bavaria (see p. 213). It is evident that here we have approached the limit of the higher forms of marine invertebrate life, having as yet nothing to show except worms and Protozoa. It is to be observed, however, that there may be somewhere Huronian deposits formed in deep and quiet waters, which may give better results, and that the unconformity between the Huronian and overlying Kewenian may indicate a lapse of time, of which monuments may yet be found. The Laurentian. Last of all we have the widely distributed Lau- rentian system of Logan, the oldest known to geologists, and which with the Huronian constitutes the great Archaean group of formations of Dana and others. In its lowest part this consists entirely of the stratified granitic rock known as gneiss, inter- bedded in some places with dark-coloured crystalline rocks or schists. This may be a part of the first- formed crust of our globe, produced under conditions 72 RELICS OF PRIMEVAL LIFE different from those of any later rocks, and incom- patible with the existence of life. The upper part of the Lauren tian system, however, known in Canada as the "Grenville Series," shows evidence of ordinary marine deposition in quiet waters, which may have been not unfavourable to the lower forms of marine life ; and though its beds have been greatly changed by heat and pressure, we can still to some extent realize the conditions of a time of comparative quiescence intervening between the underlying Lower Laurentian and the succeeding Huronian. This part of the system still contains gneisses, bedded diorites, and other rocks which may have been volcanic ; but it has also quartzites and quartzose gneisses which must have been sand- stones or shales, thick limestones, beds of carbon now in the state of graphite or plumbago, and large beds of iron ore. Such rocks were in all succeed- ing formations produced under water and by accu- mulations of the remains of plants and the hard parts of animals, in strictly sedimentary beds, usually formed slowly and without mechanical disturbance. Hence we may infer that aquatic life at least existed in this early period, and as there must have been land and water, shallows and deep tfeE-CAMBRlAlsr LIFE f^ seas, there may have been scope for various kinds of living beings. The GrenviUe period is, however, separated from the succeeding Huronian by a great interval, occupied mainly by volcanic ejections and earth-movements ; so that our Grenville series, if it contains organic remains, may be supposed to afford species differing from those of the Huronian, and to form a sort of oasis in the desert of the early pre-Cambrian world. We find that the limestones of this age actually contain remains supposed to be of. animal origin. They were first found in Canada, which contains the largest and best ex- posed area of these rocks in the world, and were brought under the notice of geologists by the late Sir William E. Logan, the first director of the Geological Survey of that country. In anticipation of details to be given later, the story of this discovery and its announcement may here be given in brief. As early as 1858, Sir William Logan had begun to suspect that certain laminated bodies found in the Laurentian limestones of the Grenville series might be of organic origin. The points which struck him were these : They differed from any known lamin- ated concretions ; they resembled the " Stromato- 74 RELICS OF PRIMEVAL LIFE porae " or layer-corals of the lower Palaeozoic rocks next in succession to the Laurentian and Huronian ; the forms were similar in all the specimens, while the mineralizing substances were different; they were found only in the limestone, and specially in one of the three great beds known in the formation, the upper limestone of the Grenville system. He exhibited specimens, and mentioned these probabili- ties at the meeting of the American Association in 1859. In 1862 it was suggested to Logan that the microscopic structure of some of the best preserved examples should be studied, and slices were accord- ingly prepared and submitted to the writer for examination. They revealed in the calcareous laminae of the specimens complicated systems of canals or tubes filled with mineral matter, which appeared to be similar to those that Carpenter had recognised in the thickened parts of the shells of modern Foraminifera. This clew being followed, large numbers of slices of the supposed fossils and of the containing limestone and of similar limestones from other parts of the world were examined. The writer also visited the localities of " Eozoon," and studied its mode of occurrence in situ. The facts ascertained were communicated to the Geo- PRE-CAMBRIAN LIFE 75 logical Society of London, the name " Eozoon Canadense" being proposed for the species. Its description was accompanied by a paper on the geological conditions by Logan, and one on the chemical conditions by Sterry Hunt, while sup- plementary notes were added by the late Dr. Carpenter and Professor T. Rupert Jones. Thus launched on the scientific world, " Eozoon " at once became a fertile subject of discussion, and volumes of more or less controversial literature have appeared respecting it. It still has its friends and opponents, and this may long continue, as so few scientific men are sufficiently acquainted on the one hand with the possibilities and conditions of the preservation of fossils in crystalline rocks, and on the other hand with the structures of modern " Protozoa." Thus, few are in a position to form an independent judgment, and " Eozoon " has met with some scepticism on the part both of biological and mineralogical specialists. To aid us in forming an opinion, it will be necessary to consider the oldest known strata of the earth's crust, and the evidence which they afford of the condition of the world when they were de- posited. As preliminary to this, we may look at the following table of pre-Cambrian formations in Canada. y6 RELICS OF PRIMEVAL LIFE SUCCESSION OF PRE-CAMBRIAN ROCKS IN CANADA, AS UNDERSTOOD UP TO 1896. (/« descending order.)- ' Etcheminian in New Brunswick, Kewenian or Upper Copper-bearing Series of Lake Superior, Signal Hill Series of Newfoundland. Chuar, and Grand Canon rocks of Colorado, etc. Red and greenish Sandstones and Shales, Con- glomerates, Igneous Outflows and Ash-rocks. Bivalve Crustacea, Mollusks, Worms, Sponges, Cystideans, Zoophytes, Protozoa, Cryptozoon. ( Unconformity!) HuRONlAN, including Hastings of Ontario, Coldbrook and Coastal of New Brunswick, Algonkian (in part). Conglomerates, Hard Sandstones, Shales and Schists, Iron Ores, Coarse Limestones, Igneous Outflows, and Ash-rocks. Worms, Sponges, Zoophytes, and Proto- zoa (Cryptozoon or Eozoon). o N o O < (^Unconformity [/]) Grenvillian or Upper Laurentian. Gneiss, Hornblendic and Micaceous Schists, Lime- stones, Quartzite, Iron Ores, Graphite. Eozoon, Archae- ozoon, Archaeospherinae, Archseophyton. Unconformity. Arch^an or Lower Laurentian. Gneiss, Hornblende Schists, with many igneous or igneo-aqueous intrusions. THE FOUNDATIONS OF THE CONTINENTS, AND THEIR GENERAL TESTIMONY AS TO LIFE n IV THE FOUNDATIONS OF THE CONTINENTS, AND THEIR GENERAL TESTIMONY AS TO LIFE "T^HAT the reader may be enabled better to *■ understand the relation of the old founda- tions or pillars of the earth to the beginning of life, and the preservation of the remains of the earliest animals, it may be well to reverse the method we have hitherto followed, and to present a theoretical or ideal historical sketch of the early history of the earth, beginning with that stage in which it may be supposed to have been a liquid mass, considerably larger than it is at present, and intensely heated, and surrounded by a vast vaporous envelope composed of all the substances capable of being resolved by its heat into a gaseous condition — a smooth and shining spheroid, invested with an enormous atmo- sphere. In such a condition its denser materials, such as the heavier metals, would settle toward the centre, and the surface would consist of lighter material 79 So RELICS OF PRIMEVAL LIFE composed of the less dense and more oxidizable sub- stances combined with oxygen, and similar in cha- racter and appearance to the slag which forms on the surface of some ores in the process of smelting. Of this slaggy material there might, however, be different layers more or less dense in proceeding from the interior to the surface. This molten sur- face would, of course, radiate heat into space ; and as it would naturally consist of the least fusible matters, these would begin to form a solid crust. We may imagine this crust at first to be smooth and unbroken, though such a condition could scarcely exist for any length of time, as the hard- ened crust would certainly be disturbed by ascend- ing currents from within, and by tidal movements without. Still, it might remain for ages as a spher- oidal crust, presenting little difference of elevation or depression in comparison with its extent. When it became sufficiently thick and cool to allow water to lie on its surface, new changes would begin. The water so condensed would be charged with acid substances which would begin to corrode the rocky surface. Penetrating into crevices and flash- ing into steam as it reached the heated interior, it would blow up masses and fragments of stone, and THE FOUNDATIONS OF THE CONTINENTS 8l would perhaps force out and cause to flow over the surface beds of molten material from below the crust, and differing somewhat from it in their com- position. All this aqueous work would accelerate the cooling and thickening of the crust, and at length a universal or almost universal heated ocean would envelope the globe, and so far as its surface was concerned, the reign of water would replace that of fire. We may pause here to con- sider the probable nature of the earth's crust in this condition. The substance most likely to predominate would be silica or quartz, one of the lighter and most infusible materials of the crust ; but which, heated in contact with alumina, lime, potash, and other earths and alkalis, forms fusible slags, enamels and glasses. One of these, composed of silica, alumina, and potash, or soda, was long ago named by the German miners felspar, a name which it still retains, though now several distinct kinds of it are dis- tinguished by different names. Another is a compound of silica with magnesia and lime, form- ing the mineral known as Amphibole or Horn- blende, and by several other names, according to its colour and crystalline form. In many deep- 6 82 RELICS OF PRIMEVAL LIFE seated rocks these minerals are formed together, and having crystallized out separately give a spotted and granular character to the mass. Naturally colourless, all these minerals, and es- pecially the felspar and hornblende, are liable to be coloured with different oxides of iron, the felspar usually taking a reddish, and the hornblende a greenish or blackish hue. Now, if we examine a fragment of the oldest or fundamental gneiss or granite, we shall see glassy grains of quartz, reddish or white flat-surfaced crystals of felspar, and dark- coloured prisms of hornblende. When destitute of any arrangement in layers, the rock is granite ; when arranged more or less in flakes or laminae, it is gneiss, the structure of which may arise either from its having been formed in successive beds, or from its having been flattened or drawn out by pressure. These structures can be seen more or less distinctly in any ordinary coarse-grained granite, or with the lens or microscope in finer varieties. The Lower Laurentian rocks of our section con- sist essentially of the materials above described, with a vast variety in the proportions and arrange- ments of the constituent minerals. There is, there- THE FOUNDATIONS OF THE CONTINENTS 83 fore, nothing to prevent us from supposing that these rocks are really remains of the lower portions of the original crust which first formed on the sur- face of our cooling planet, though the details of their consolidation and the possible interactions of heat and heated water may admit of much discus- sion and difference of opinion. But after the formation of a crust and its cover- ing in whole or in part with heated water, other changes must occur, in order to fit the earth for the abode of life. These proceeded from the tensions set up by the contraction and expansion of the interior heated nucleus and the solid crust — a complicated and difficult question, when we con- sider its laws and their mode of operation, but which resulted in the folding and fracturing of the crust along long lines which are parts of great circles of the earth, running in N.E. and S.W. and N.W. and S.E. directions ; and these ridges, which in the earliest Archaean period must have attained to great height and very rugged outlines, formed the first rudiments of our mountain chains and continents. Those constituting the Laurentian nucleus of North America — a very simply outlined continent — form a case in point (Fig. 18). 84 RELICS OF PRIMEVAL LIFE The elevation of these mountain ridges forced the waters to recede into the lower levels. As the old psalm of creation has it, — "The mountains ascend, the valleys descend into the place Thou hast founded for them," and so sea-basins and land were produced. Milton merely paraphrases this when he says, — " The mountains huge appear Emergent, and their broad, bare backs upheave Into the clouds ; their tops ascend the sky. So high as heaved the tumid hills, so low Down sunk a hollow bottom wide and deep, Capacious bed of waters." Englishmen have been accused of taking their ideas of creation from Milton rather than from nature or the Bible. Milton had not the guidance of modern geology. His cosmology is entirely that of a close student of the Biblical narrative of creation. He is in many respects the best commen- tator on the early chapters of Genesis, because he had a very clear conception of the mind of the writer, and the power of expressing the ideas he derived from the old record. For the same reason he is the greatest bard of creation and primitive man, and surprisingly accurate and true to nature. THE FOUNDATIONS OF THE CONTINENTS 85 Then began the great processes of denudation and sedimentation to which we owe the succeeding rock formations. The rains descended on the mountain steeps, and washed the decaying rocks as sand, gravel and mud into the rivers and the Fig. iS. — Map of Laurentian, North America. Showing the protaxis or nucleus of the continent. sea. The sea itself raged against the coasts, and cut deeply into their softer parts ; and all the detritus thus produced by atmospheric and marine denudation was spread out by the tides and currents in the. bed of the ocean, and its gulfs and 86 RELICS OF PRIMEVAL LIFE seas, forming the first aqueous deposits, while the original land must have been correspondingly re- duced. The sea might still be warm, and it held in solu- tion or suspension somewhat different substances from those now present in it, and the land was at first a mere chaos of rocky crags and pinnacles. But so soon as the temperature of the waters fell somewhat below the boiling point, and as even a little soil formed in the valleys and hollows of the land, there was scope for life, provided that its germs could be introduced. On a small scale there was something of this same kind in the sea and land of Java, after the great eruption of Krakatoa, in 1883. The bare and arid mountain left after the eruption, began, in the course of a year, to be occupied by low forms of vegetable life, gradually followed by others, and verdure was soon restored. The once thickly peopled sea-bottom, so prolific of life in these warm seas, but buried under many feet of volcanic ashes and stones, soon began to be re-peopled, and is now probably as populous as before. But in this case there were plenty of spores of lichens, mosses, and other bumble plants to be wafted to the desolate The foundations of the continents 8; cone, and multitudes of eggs and free-swimming germs of hundreds of kinds of marine animals to re-people the sea-bottom. Whence were such things to come from to occupy the old Archaean hills and sea-basins? and all our knowledge of nature gives us no answer to the question, except that a creative power must have intervened ; but in what manner we know not. That this actuallj- occurred, we can, however, be assured by the next succeeding geological formation. We have seen that the granitic and gneissic ridges could furnish pebbles, sand, and clay, and these once deposited in the sea-bottom could be hardened into con- glomerate, sandstone and slate. But beside these we have in the next succeeding or Upper Lauren- tian formation rocks of a very different character. We have great beds of limestone and iron ore, and deposits, of carbon or coaly matter, now in the peculiar state of graphite or plumbago, and it is necessary for us to inquire how these could originate independently of life. In modern seas limestone is forming in coral reefs, in shell beds, and in oceanic chalky ooze composed of minute microscopic shells ; but only in rare and exceptional instances is it formed in any other RELICS OF PRIMEVAL LIFE way; and when we interrogate the old limestones ^^^?^^^^^ Yjg. 10. Distribution of Grenville Limestone m the uistrict north of Papineauville, with section showing supposed arrangement of the beds. Scale of Map 7 miles to one inch. See also Dr. Bonney's paper, Geot. Mag., July, 1895. Dotted area : Limestone. Horizontal lines : Upper gneiss (fourth gneiss of Logan). Vertical lines : Lower gneiss (tliird gneiss of J^ogan). Diagonal lines : Overlying Cambrian and Cambro-Silurian (Ordovician), (See also Fig. 19A.) and marbles which form parts of the land, they THE FOUNDATIONS OP THE CONTINENTS 89 give us evidence that they also are made up of calcareous skeletons of marine animals or fragments of these. Now when we find in the Grenvillian series, the first oceanic group of beds known to us, great and widely extended limestones, thousands of feet in thickness, and rivalling in magnitude those of any succeeding period, we naturally infer that marine life was at work. No doubt the primitive sea contained more lime and magnesia than the present ocean holds in solution ; but while this might locally favour the accumulation of inorganic limestones, it cannot account for so great and extensive deposits. On the other hand, a sea rich in lime would have afforded the greatest facilities for the growth of those marine plants which accumulate lime, and through these for the nutrition of animals forming calcareous shells or corals. Thus we have pre- sumptive evidence that there must have been in the Upper Laurentian sea something corresponding to our coral reefs and shell-beds, whatever this something may have been. These limestones, however, demand more par- ticular notice (Fig. 19). One of the beds measured by the officers of the Geological Survey is stated to be 1,500 feet in 90 RELICS OF PRIMEVAL LIFE ' thickness, another is 1,250 feet thick, and a third 750 feet ; making an aggregate of 3,500 feet.^ These beds may be traced, with more or less inter- ruption, for hundreds of miles. Whatever the origin of such limestones, it is plain that they in- dicate causes equal in extent, and comparable in power and duration, with those which have produced the greatest limestones of the later geological periods. Now, in later formations, limestone is usually an organic rock, accumulated by the slow gathering from the sea-water, or its plants, of cal- careous matter, by corals, foraminifera, or shell-fish, and the deposition of their skeletons, either entire or in fragments on the sea-bottom. The most friable chalk and the most crystalline limestones have alike been formed in this way. We know of no reason why it should be different in the Lauren- tian period. When, therefore, we find great and conformable beds of limestone, such as those de- scribed by Sir William Logan in the Laurentian of Canada, we naturally imagine a quiet sea-bottom, in which multitudes of animals of humble organi- zation were accumulating limestone in their hard parts, and depositing this in gradually increasing ' Logan : " Geology of Canada," p. 45. THE FOUNDATIONS OF THE CONTINENTS 9I thickness from age to age. Any attempts to account otherwise for these thick and greatly ex- tended beds, regularly interstratified with other deposits, have so far been failures, and have arisen either from a want of comprehension of the nature and magnitude of the appearances to be explained, or from the error of mistaking the true bedded limestones for veins of calcareous spar. Fig. 19A, — Attitude of Limestone at CSte St. Pierre (see Map, p. 88). (a) Gneiss band in the Limestone. (3) Limestone with Eozoon. (c) Dioriteand Gneiss. Again, in the original molten world, it seems likely that most of the carbon present — at least, at the surface — was in the atmosphere in the gaseous form of carbon dioxide. This might be dissolved by the rain and other waters ; but we know in the modern world no agency which can decompose this compound and reduce it to ordinary 0^ kELICS OF tRlMEVAL LIFE carbon or coal, except that of living plants, which are always carrying on this function to an enor- mous extent. We know that all our great beds of coal and peaty matter are. composed of the remains of plants which took their carbon from the air and the waters in past times. We also know that this coaly vegetable matter may, under the influence of heat and pressure, when buried in the earth, be converted into anthracite and into graphite, and even into diamond. It is true that an emi- nent French chemist * has shown that graphite and hydrocarbons may be produced from some of the metallic compounds of carbon which may have been formed under intense heat in the interior of the earth, by the subsequent action of water on such compounds ; but there is nothing to show that this can have occurred naturally, unless in very exceptional cases. Now in the Grenvillian system in Canada there is not only a vast quantity of carbon diffused through the limestones, and filling fissures in other rocks, into which it seems to have been originally introduced as liquid bitumen, but also in definite beds associated with earthy matter, ' Henri Moissan, "Proceedings Royal Society," June, 1896. THE FOUNDATIONS Of THE CONTINENTS 93 and sometimes ten to twelve feet thick. The occurrence of this large amount of carbon warrants us in supposing that it represents a vast vegetable growth, either on the land or in the sea, or both. In like manner, in later geological periods, beds of iron ore are generally accumulated as a conse- quence of the solvent action of acids produced by vegetable decay, as in the clay ironstones of the coal formation and the bog iron ores of later times. Thus the beds of magnetic iron occurring in the Upper Laurentian may be taken as evidences, not of vegetable accumulation, but of vegetable decay. May not also the great quantity of calcium phos- phate mined in the Grenville series in Canada, indicate, as similar accumulations do in later forma- tions, the presence of organisms having skeletons of bone earth ? With reference to the carbon and iron ore of the Grenville series, I may quote the following from a paper published in the Journal of the Geological Society of London in 1870: — " The quantity of graphite in the Upper Lauren- tian series is enormous. In a recent visit to the township of Buckingham, on the Ottawa River, I examined a band of limestone believed to be a 94 RELICS OF PRIMEVAL LIFE continuation of that described by Sir W. E. Logan as the Green Lake Limestone. It was estimated to amount, with some thin interstratified bands of gneiss, to a thickness of 600 feet or more, and was found to be filled with disseminated crystals of graphite and veins of the mineral to such an extent as to constitute in some places one-fourth of the whole ; and making every allowance for the poorer portions, this band cannot contain in all a less vertical thickness of pure graphite than from twenty to thirty feet. In the adjoining township of Locha- ber Sir W. E. Logan notices a band from twenty- five to thirty feet thick, reticulated with graphite veins to such an extent as to be mined with profit for the mineral. At another place in the same district a bed of graphite from ten to twelve feet thick, and yielding twenty per cent, of the pure material, is worked. When it is considered that graphite occurs in similar abundance at several other horizons, in beds of limestone which have been ascertained by Sir W. E. Logan to have an aggregate thickness of 3,500 feet, it is scarcely an exaggeration to maintain that the quantity of car- bon in the Laurentian is equal to that in similar areas of the Carboniferous system. It is also to THE FOUNDATIONS OF THE CONTINENTS 95 be observed that an immense area in Canada appears to be occupied by these graphitic and Eozoon limestones, and that rich graphitic deposits exist in the continuation of this system in the State of New York ; while in rocks believed to be of this age near St. John, New Brunswick, there is a very thick bed of graphitic limestone, and associ- ated with it three regular beds of graphite, having an aggregate thickness of about five feet' " It may fairly be assumed that in the present world, and in those geological periods with whose organic remains we are more familiar than with those of the Laurentian, there is no other source of unoxidized carbon in rocks than that furnished by organic matter, and that this has obtained its car- bon in all cases, in the first instance, from the deoxidation of carbonic acid by living plants. No other source of carbon can, I believe, be imagined in the Laurentian period. We may, however, sup- pose either that the graphitic matter of the Lauren- tian has been accumulated in beds like those of coal, or that it has consisted of diffused bituminous ' Matthew, in Quart. Joum. Geol. Soc, vol. xxi. p. 423. " Acadian Geology," p. 662. g6 RELICS OF PRIMEVAL LIFE matter similar to that in more modern bituminous shales and bituminous and oil-bearing limestones. The beds of graphite near St. John, some of those in the gneiss at Ticonderoga in New York, and at Lochaber and Buckingham and elsewhere in Canada, are so pure and regular that one might fairly com- pare them with the graphitic coal of Rhode Island. These instances, however, are exceptional, and the greater part of the disseminated and vein graphite might rather be compared in its mode of occur- rence to the bituminous matter in bituminous shales and limestones. " We may compare the disseminated graphite to that which we find in those districts of Canada in which Silurian and Devonian bituminous shales and limestones have been metamorphosed and converted into graphitic rocks not dissimilar to those in the less altered portions of the Laurentian.*^ In like manner it seems probable that the numerous reticu- lating veins of graphite may have been formed by the segregation of bituminous matter into fissures and planes of least resistance, in the manner in ' Granby, Melbourne, Owl's Head, etc., " Geology of Canada," 1863, p. 599. THE FOUNDATIONS OF tHE CONTINENTS 97 which such veins occur in modern bituminous lime- stones and shales. Such bituminous veins occur in the Lower Carboniferous limestone and shale of Dorchester and Hillsborough, New Brunswick, with an arrangement very similar to that of the veins of graphite ; and in the Quebec rocks of Point Levi, veins attaining to a thickness of more than a foot are filled with a coaly matter having a trans- verse columnar structure, and regarded by Logan and Hunt as an altered bitumen. These Palaeozoic analogies would lead us to infer that the larger part of the Laurentian graphite falls under the second class of deposits above mentioned, and that, if of vegetable origin, the organic matter must have been thoroughly disintegrated and bituminized be- fore it was changed into graphite. This would also give a probability that the vegetation implied was aquatic, or at lesist that it was accumulated under water. " Dr. Hunt has, however, observed an indication of terrestrial vegetation, or at least of subaerial decay, in the great beds of Laurentian iron ore. These, if formed in the same manner as more modern deposits of this kind, would imply the reducing and solvent action of substances produced in the 7 98 RELICS OF PRIMEVAL LIFE decay of plants. In this case such great ore beds as that of Hull, on the Ottawa, 70 feet thick, or that near Newborough, 200 feet thick,* must represent a corresponding quantity of vegetable matter which has totally disappeared. It may be added that similar demands on vegetable matter as a deoxidizing ^gent are made by the beds and veins of metallic sulphides of the Laurentian, though some of the latter are no doubt of later date than the Laurentian rocks themselves. " It would be very desirable to confirm such con- clusions as those above deduced by the evidence of actual microscopic structure. It is to be observed, however, that when, in more modern sediments, algae have been converted into bituminous matter, we cannot ordinarily obtain any structural evidence of the origin of such bitumen, and in the graphitic slates and limestones derived from the metamor- phosis of such rocks no organic structure remains. It is true that, in certain bituminous shales and limestones of the Silurian system, shreds of organic tissue can sometimes be detected, and in some cases, as in the Lower Silurian limestone of the > " Ceolo|ry of Canada," 1863. THE FOUNDATIONS OF THE CONTINENTS 99 La Cloche mountains in Canada, the pores of brachiopodous shells and the cells of corals have been penetrated by black bituminous matter, form- ing what may be regarded as natural injections, sometimes of much beauty. In correspondence with this, while in some Laurentian graphitic rocks, — as, for instance, in the compact graphite of Clarendon, — the carbon presents a curdled appearance due to segregation, and precisely similar to that of the bitumen in more modern bituminous rocks, I can detect in the graphitic limestones occasional fibrous structures which may be remains of plants, and in some specimens vermicular lines, which I believe to be tubes of Eozoon penetrated by matter once bituminous, but now in the state of graphite. " When Palaeozoic land-plants have been con- verted into graphite, they sometimes perfectly retain their structure. Mineral charcoal, with structure, exists in the graphitic coal of Rhode Island. The fronds of ferns, with their minutest veins perfect, are preserved in the Devonian shales of St. John, in the state of graphite ; and in the same formation there are trunks of Conifers {Dadoxylon ouangon- dianuni) in which the material of the cell-walls has been converted into graphite, while their cavities ICX) RELICS OF PRIMEVAL LIFE have been filled with calcareous spar and quartz, the finest structures being preserved quite as well as in comparatively unaltered specimens from the coal-formation.^ No structures so perfect have as yet been detected in the Laurentian, though in the largest of the three graphitic beds at St John there appear to be fibrous structures which I be- lieve may indicate the existence of land-plants. This graphite is composed of contorted and slicken- sided laminae, much like those of some bituminous shales and coarse coals ; and in these there are occasional small pyritous masses which show hollow carbonaceous fibres, in some cases presenting ob- scure indications of lateral pores. I regard these indications, however, as uncertain ; and it is not as yet fully ascertained that these beds at St. John are on the same geological horizon with the Gren- ville series of Canada, though they certainly under- lie the Cambrian series of the St. John or Acadian group, and are separated from it by beds having the character of the Huronian, and thus come, approxi- mately at least, into the same geological position. •■"Acadian Geology," p. 535. In calcified specimens the structures remain in the graphite after decalcification by an acid. THE FOUNDATIONS OF THE CONTINENTS lOI " There is thus no absolute impossibility that distinct organic tissues may be found in the Lau- rentian . graphite, if formed from land-plants, more especially if any plants existed at that time having true woody or vascular tissues ; but it cannot with certainty be affirmed that such tissues have been found. It is possible, however, that in the Lau- rentian period the vegetation of the land may have consisted wholly of cellular plants, as, for example, mosses and lichens ; and if so, there would be com- paratively little hope of the distinct preservation of their forms or tissues, or of our being able to dis- tinguish the remains of land-plants from those of Algae. The only apparent plant of the Laurentian to which a name has been given, Archceopkyton of Britton, from New Jersey, consists of ribbon-like strips, destitute of apparent structure, and which, if they are of vegetable origin, may have belonged to either of the leading divisions of the vegetable king- dom. I have found similar flat frond-like objects in the limestone of the Grenville series, at Lachute, in Canada. " We may sum up these facts and considerations in the following statements : — First, that somewhat obscure traces of organic structure can be detected I02 RELICS OF PRIMEVAL LIfE in the Laurentian graphite ; secondly, that the general arrangement and microscopic structure of the substance corresponds with that of the carbon- aceous and bituminous matters in marine formations of more modern date ; thirdly, that if the Laurentian gr'aphite has been derived from vegetable matter, it has only undergone a metamorphosis similar in kind to that which organic matter in metamorphosed sediment of later age has experienced ; .fourthly, that the association of the graphitic matter with organic limestone, beds of iron ore, and metallic sulphides, greatly strengthens the probability of its vegetable origin ; fifthly, that when we consider the immense thickness and extent of the Eozoonal and graphitic limestones and iron ore deposits of the Laurentian, if we admit the organic origin of the limestone and graphite, we must be prepared to believe that the life of that early period, though it may have existed under low forms, was most copiously developed, and that it equalled, perhaps surpassed, in its results, in the way of geological accumulation, that of any subsequent period." Let us take, in connection with all this, the fact that we are dealing with the deposits of the earliest oi.ean known to us — an ocean warm and abounding THE FOUNDATIONS OF THE CONTINENTS IO3 in the mineral matters suitable for the skeletons of humble animals, and fitted to nourish aquatic plants. The conditions were certainly favourable to an exu- berant development of the lower forms of marine Figs. 20 and 2\. — Bent and dislocated Quartzite, in contorted schistt interstratified with Grenville Limestone, near Montebello. The Quartzites have been broken and displaced, while the schist.*; have been bent and twisted. In the immediate vicinity the same beds may be seen slightly in- clined and undisturbed. life ; and in later times, when such conditions pre- vail, we generally find that life has been introduced to take advantage of them. The prudent farmer does not usually allow his best pasture to remain I04 RELICS OF PRIMEVAL LIFE untenanted with flocks and herds, and the Great Husbandman of nature has, so far as we know, been similarly careful. I add two sections showing the local disturbances of beds of quartzite and schist associated with the Grenville limestones (Figs. 20 and 21, page 103). PROBABILITIES AS TO LAURENTIAN LIFE, AND CONDITIONS OF ITS PRESERVATION 106 PROBABILITIES AS TO LAURENTIAN LIFE, AND CONDITIONS OF ITS PRESERVATION WJ^ '^^ve seen that the mineral constitution of the Upper Laurentian affords evidence that in this age there were already land and water, and that the processes by which the land is being worn down, and its materials deposited on the sea-bottom, were in full operation ; while the absence of any evidence of violent wave-action, and the presence of thick deposits of limestone, coaly matter, iron ore, and fine-grained beds of sediment, indicates a time of rest and quiescence. All these conditions were favourable to the presence of life, and we should expect to find in such a period some sign of its commencement. But here we are met by a formidable difficulty. If the beds of the Grenville series were originally deposits in a quiet sea, they are, as now existing in the old Laurentian hills and valleys, very much changed from their original condition. They have, 107 I08 RELICS OF PRIMEVAL LIFE in short, experienced the changes known to geologists by the formidable word metamorphism, whereby they have lost the more obvious characters of ordinary aqueous deposits, and have assumed new and strange forms. Dr. Adams, of Montreal, has taken the pains to collect a number of chemical analyses of the gneisses and schists or crystalline slates of the Grenville series, and finds that, however unlike to more modern shales and clays, they have substan- tially the same chemical composition. Now if they were originally such shales and clays, it has happened to them that the ingredients of the clays have rearranged themselves in new forms and become crystalline. We are familiar in a small way with such changes when brick clay, over-heated in the kiln, becomes fused into slag or vitrified ; and if such slag were allowed to cool very slowly, it would present different kinds of crystalline minerals. We actually see changes of this kind in the substance of bricks which have been long exposed to intense heat in the walls of furnaces. Now in the crust of the earth, very old rocks, buried under newer deposits, and exposed to the heat of the interior molten rocks, experience such changes on a great scale ; and there is one kind of influence present in LAURENTIAN LIFE 109 the bowels of the earth which we in our experi- ments cannot easily imitate or understand, namely, the action of superheated water prevented by pres- sure from escaping as steam, and permeating the whole substance of deposits, which are thus, baked at a high temperature in presence of water, instead of being exposed to mere dry heat, as in our kilns and furnaces. The study of the partial changes which have passed on later sediments where in contact with volcanic masses once intensely heated, enables us to understand the greater and more ex- tensive inetamorphism of the oldest rocks. Thus a mere mud becomes glorified by metamorphic cry- stallization into a micaceous schist. We have taken ordinary clay as an example; but under the same processes sand has been converted into a compact quartzite, ordinary limestone into crystalline marble, clay-ironstone into magnetic iron ore, coal into graphite, and lavas or volcanic ashes into hard crystalline granites, gneisses, or pyroxene rocks or hornblendic schists, according to their original com- position. There may exist portions of these old rocks which have been exempt from such alteration, but hitherto we have not been able to find them, and they are probably under the ocean bed, or no RELICS OF PRIMEVAL LIFE deeply buried beneath later rocks, while the parts exposed are precisely those which have by their crumpling and pressure, and the influence of internal heat, become most hardened and altered, and have therefore best resisted denudation. We need not therefore be astonished if any organic remains ori- ginally present in such rocks should have perished, or should have been subjected to such changes of composition and form as to have altogether lost their original characters. The searcher for fossils in such rocks has to expect that these can have been preserved only under very rare and excep- tional circumstances. We have now to consider what these circumstances are, and for simplicity may suppose that we are endeavouring to discover in a crystalline limestone the remains of animals having a skeleton of limestone, as is the case with most shell -fishes and corals, and with many Protozoa and marine worms. In regard to these, we have to consider what may happen to them when they are imbedded in calcareous marl or ooze, or the limestone which results from the hardening of such materials ; and we have to bear in mind that such organisms usually consist of hard, stony walls or partitions, en- closing cavities originally filled with the soft parts LAURENTIAN LIFE I 1 1 of the animal which may be supposed to have dis- appeared by decay before or during the mineraliza- tion of its skeleton. So long as the imbedding mass continues soft and incoherent, shells, corals, etc., can be recovered in a condition similar to that of recent specimens, except that they may have become bleached in colour and brittle in texture, owing to the removal of organic matter intimately associated with the lime, and that their cavities may have been filled with sand or silt washed into them, or with calcite or calcareous spar introduced in solution in water. But if the contain- ing mass has become a hard stone, the material filling the interior of our shell or coral has expe- rienced a similar change ; and when we break open the stone, we may obtain the specimen, now hard, solid, and heavy, but still showing more or less of its outer surface and markings, and possibly to some extent also its internal structure when it is sliced and studied under the microscope. But if the whole mass has been metamorphosed, and has be- come crystalline, the contained fossil and its contents may have experienced a similar change, and may have so coalesced with the containing matrix that it is no longer separable from it. Even in this case, 112 RELICS OF PRIMEVAL LIFE however, if the whole is reduced to a thin transparent slice and examined microscopically, some traces may be found of the external and internal limiting lines of the fossil, and even of its minute structures, which often cause it to. present an appearance granular, Fig. 22. — Section of " Trenton Limestone" (^magnified'). Showing its composition of fi-agments of calcareous fossils. cellular, or otherwise different from that of the en- closing matrix. It requires, however, both skill and care to detect organic remains in such circumstances, and they may often escape observation, except when, as in many old crystalline limestones, the fossils are darkened in whole or in part with coaly matter LAURENTIAN LIFE "3 derived from the decay of their own organic substance. The crystalline Trenton limestone of Montreal, used there as a building stone, is an excel- lent example (Fig. 22). It is otherwise, however, when the calcareous fossils have been filled or injected with some mineral matter different from the matrix, as, for example, silica or some silicate, oxide or sulphide of iron. D 5 7 |iiii| • Ml ,1.. •>M I 1 Fig. 23. — Diagram of different States of Fossiliaation of the Cell of a Tubulate Coral. (a) Natural condition, (i) Cell filled with calcitc. if) Walls calcite, filling silica. (d) Walls silica, filling calcite. (e) Both walls and calcite silica. All these conditions are found in the fossil corals of the corniferous Limestone of Canada — Middle Permian. In this case the texture, colour, or hardness of the filling appear difierent from those of the limestone, and may be seen in a fresh fracture or polished slice ; or when the rock is weathered, the hard mine- ralizing substance may project from the surface of the specimens, or may be disclosed by treating the surface with a weak acid. The figures here given may suffice to show some of these conditions of 8 114 RELICS OF PRIMEVAL LIFE mineralization in ordinary limestones, and the effects which they produce (Fig. 23). The mineral matters which thus aid in preserving fossils are of various kinds, and the whole subject is a very curious one ; but for the present we may content ourselves with two kinds of mineralization — that by silicates and that by magnesian limestone or dolomite. From the bottom of modern seas the dredge often brings up multitudes of minute shells, especially those of the simple gelatinous Protozoa, known as Foraminifera, whose internal cavities and pores have been filled with a greenish mineral composed of silica, iron and potash, combined with water (or, chemically speaking, a hydrous silicate of iron and potassium), which is named glauconite from its bluish-green colour — a name which we shall do well to remember. In such compounds, bases of similar chemical pro- perties often replace one another, so that various glauconites differ somewhat in composition, the iron being in part often replaced by alumina or magnesia, and the potash by soda. The combined water also differs somewhat in its percentage. When minute shells fossilized in this way are treated with an acid so as to remove the calcareous shell itself, the en- closed silicate remains as a beautiful cast or core, LAURENTIAN LIFE IIS representing all the forms of the interior, and any pores that may have penetrated the walls, and also perfectly representing the soft gelatinous body of the animal which once tenanted the shells (Fig. 24). (See also Fig. 25 at end of chapter.) Fig. 24. — Cast of Cavities of J-'o/ystomella in Ciautuiiue ^magnified). After a photograph from Dr. Carpenter, and mounted specimens from liis collection. When we examine oceanic sediments of older date, we find similar fillings in limestones, chalks, and sandstones of various ages, some of the latter containing glauconite so abundantly as to bear the name of greensands, from their colour ; and in these older examples we more frequently find alu- ll6 RELICS OF PRIMEVAL -LIFE mina and magnesia occupying a large place in the mineralizing silicate. Fig. 24A gives two illustrations of this — one a crinoidal stem from the Silurian of New Brunswick, injected with a silicate of alumina, Fig. 24A. — {a) Joint of Crinoid injected with a Hydrous Silicate, Silurian, Pole Hill, New Brunswick. ( X 25. ) (b) Spiral Shell injected with a Hydrous Silicate allied to Serpentine, near Llangwyllog, North Wales, (x 25.) iron, magnesia and potash ; the other a spiral shell from more ancient perhaps Cambrian rocks in Wales, filled with a silicate apparently more nearly related to serpentine. Further examples will be re- ferred to in an appended note. LAURENTIAN LIFE II7 We may now consider shortly the relation of dolomite, or the mixed carbonates of lime and mag- nesia, to the preservation of fossils. The presence of dolomite or magnesian limestone in these beds does not affect the conclusion as to their probable organic origin. This form of limestone occurs abun- dantly in later formations, and is even forming in connection with coral deposits in the modern ocean. Dana has shown this by his observations on the occurrence of dolomite in the elevated coral island of Matea in Polynesia,^ under circumstances which show that it was formed in the lagoon of an ancient coral atoll, or ring-shaped island, while he finds that coral and coral sands of the same elevated reef contain very little magnesia. He concludes that the introduction of magnesia into the consolidating under-water coral sand or mud has apparently taken place — "(i) In sea-water at the ordinary tempera- ture; and (2) without the agency of any other mineral water except that of the ocean"; but the sand and mud were those of a lagoon in which the saline matter was in process of concentration by evaporation under the solar heat. Klement has » « Corals and Coral Islands," p. 356, etc. Il8 RELICS OF PRIMEVAL LIFE more recently taken up tbig fact in the way of experinient, and finds that, while in the case of ordinary calcite this action is slow and imperfect, with the aragonite which constitutes the calcareous framework of certain corals/ and at temperatures of 6 Fig, 35. — Structure of small specimen of Eozoon, calcareous matter removed, I. Natural size. 2, Acervuline cells of upper part. 3. Group of the same coalesc* ing into a lamina with tuberculated surface. 4. Laminse with tuberculated surfaces in section. (See also Fig. 36.) 165 THE DAWN OF LIFE iS7 larger canals are filled with serpentine of a light green or - olive colour, and the finer tubuli are in- jected with dolomite. It may also be observed Fig. 36. — Decalcified Eozoon, in section, slightly enlarged. Showing the character of the sarcodous laminae now replaced by Serpentine. that the serpentine in the larger cavities often shows a banded structure, as if it had been de- posited in successive coats, and the canals are sometimes lined with a tubular film of serpentine, is8 Relics of primeval life with a core or axis of dolomite, which also ex- tends into the finer tubuli of the surfaces of the laminae. This, on the theory of animal origin, is the most perfect state of preservation, and it equals anything I have seen in calcareous organisms of later periods. This state of perfection is, however, naturally of infrequent occurrence. The finer tubuli Fig. 37. — Finest Tubuli filled with Dolomite {magnified). are rarely perfect or fully infiltrated. Even the coarser canals are not infrequently imperfect, while the laminjE themselves are sometimes crumpled, crushed, faulted, or penetrated- with veins of chry- sotile or of calcite. In some instances the cal- careous laminae are replaced by dolomite, in which case the canal-systems are always imperfect or obsolete. The laminae of the test itself are also in THE DAWN OF LIFE IS9 some eases replaced by serpentine in a flocculent form. At the opposite extreme are specimens, or portions of specimens, in which the chambers are obliterated by pressure, or occupied only with calcite. In such cases the general structure is entirely lost to view, and scarcely appears in weathering. It can be detected only by micro- FlG. 38. — Plan of arrangement of Canals in Lamina of Eozoon. scopic examination of slices, in parts where the granular structure or the tubulation of the calcite layers has been preserved. All palaeontologists who have studied silicified fossils in the older rocks are familiar with such appearances. It has been alleged by Mobius and others that the canal-systems and tubes present no organic regularity. This difficulty, however, arises solely from imperfect specimens or inattention to the necessary results of slicing any system of ramify- i6o RELICS OF PRIMEVAL LIFE ing canals. In Eozoon the canals form ramifying groups in the middle planes of the laminae, and proceed at first almost horizontally, dividing into smaller branches, which ultimately give off brushes of minute tubuli running nearly at right angles to the surfaces of the lamina, and forming the extremely fine tubulation which Dr. Carpenter regarded as J^o o "^ o di > o o ^T <-^ O i^ O Fig. 39. — Cross section of minute Tubuli, about S microms. in diameter {magnified). the proper wall (Figs. 38, 39). In my earlier de- scription I did not distinguish this from the canal- system, with which its tubuli are inwardly con- tinuous. Dr. Carpenter, however, understood this arrangement, and has represented it in his figures ^ (see also Fig. 28). It is evident that in a struc- ture like this a transverse or oblique section will show truncated portions of the larger tubes appar- ' " Ann. and Mag. Nat. Hist.," ser. 4, xiii., p. 456, figs. 3, 4. THE DAWN OF LIFE l6l ently intermixed with others much finer and not continuous with them, except very rarely. Good specimens and many slices and decalcified por- tions are necessary to understand the arrangement This consideration alone, I think, entirely invali- dates the criticisms of Mobius, and renders his large and costly figures of little value, though his memoir is, as I have elsewhere shown, liable to other and fatal objections.* It has been pretended that the veins of chry- sotile, when parallel to the laminae, cannot be distinguished from the minute tubuli terminating on the surfaces of the laminae. I feel confident, however, that no microscopist who has seen both, under proper conditions of preservation and study, could confound them. The fibres of chrysotile are closely appressed parallel prisms, with the optical properties of serpentine. The best preserved speci- mens of the " proper wall " contain no serpentine, but are composed of calcite with extremely minute parallel cylinders of dolomite about five to ten microms. in diameter, and separated by spaces greater than their own diameter (Figs. 40, 41). In > " Museum Memoir," pp. 50 et seq. II 1 62 RELICS OF PRIMEVAL LIFE the rare eases where the cylinders are filled with serpentine, they are, of course, still more distinct and beautiful. At the same time, I do not doubt that observers who have not seen the true tubu- :V-0':' g^JCLUSIONS 285 modem period, and endeavouring to discover which of our so-called species are original types and which are mere derivative varieties or races. It is evident that nothing is gained here by assuming that the whole geological record is but one of innumerable vast aeons of seons, which have gone on in endless succession. If the world is made to stand on an elephant, and this on a tor- toise, and this on lower forms, it helps us not at all if the last supporter must stand on nothing. The difficulty thus postponed only becomes greater ; and at the end we have to imagine, not only life and organization, but even matter and energy as fortuitously originating or creating themselves, un- less produced by an Almighty Eternal Will. In pursuing studies of this kind, it is best for the present to content ourselves with tracing the continuous chains of similar creatures throughout their extension in geological time, rather than to seek for connecting links between different lines of being. I endeavoured some years ago to give a popular outline of this method in a little work en- titled " The Chain of Life in Geological Time." * ' Religious Tract Society, London ; Revell Publishing Co., New York, Chicago, and Toronto. 286 RELICS OF PRIMEVAL LIFE Taking, for example, the earliest Protozoa — the Foraminifera and Radiolaria — we find two lines of being that in endless varieties, but with little material change, extend from the earliest periods to the present time. In successive ages they are represented by families, genera, and species, which are regarded as distinct, and known by different names. But these humble animals are very vari- able, and what seem to us to be new types may be merely varieties of ancestral forms. We might even affirm that, for all we know, these two great groups, as they exist in the present ocean, are lineal descendants of those that flourished in the Eozoic. We could not prove this, unless we were to find somewhere a continuous succession of deep-sea de- posits that would show the gradual changes that had occurred. On the other hand, it is hard to believe that one individual life, so to speak, could have con- tinued unimpaired to animate successive and increas- ing masses of matter in all the vast time extending from the Eozoic to the modern. It is also at least equally possible that the causes and conditions, what- ever they were, that produced the earliest Protozoa may have acted again and again in later times, origi- nating new lines of descent with renewed vitality. SOME GENERAL CONCLUSIOfJS 387 Still, the tracing of these almost incredibly long lines of descent, if they are such, is a proper, though difficult, subject of scientific research, what- ever may be the result. Something has been attempted in this direction over limited portions of time ; but a vast amount of patient labour is re- quired before certainty can be attained even in this department of investigation. When, on the other hand, we turn to the ques- tion whether such lines of creation or descent have given off branches leading to new types, as, for instance, from Protozoa to various Crustaceans or Mollusks, we are entirely destitute of facts, and the statement lately made by a leading agnostic evolu- tionist, that " if there is any truth in the doctrine of evolution, every class of the animal kingdom must be vastly older than the past records of its appearance on the surface of the globe," shows us that all the attempts to construct genealogical trees of the descent of animals are, so far as at present known, quite visionary. It seems, indeed, that each leading line, as we trace it back, ends in a blind alley, just where we might suppose that it was about to pass into another path. This is one reason of the frequent complaints as to the imper- 288 RELICS OF PRIMEVAL LIFE fection of the geological record, and of the occur- rence of " missing links " between different types of being. The only feasible explanations of this are as yet the suppositions that the times of intro- duction of new types may have been unfavourable to the preservation of their remains, or that the first representatives of each new group were soft-bodied animals incapable of preservation, or that they happened to be introduced in regions yet unex- plored. But such accidents could scarcely have been the rule in every case. Even in relation to man him- self, he is still man in all the deposits in which we can find his remains, and as remote from the apes of his time, in so far as we know, as he is from those now his contemporaries. It would seem, in short, as if, ashamed of his humble origin, he had carefully obliterated his tracks in ascending from his lowly parentage to the dignity of humanity. But in this he is only following the example of other animals, his predecessors. We may, as is now constantly done by evolutionists, fill up these gaps by plausible conjectures ; but this is not a scientific mode of procedure, unless we are content to regard these conjectures as working hypotheses in aid of researches yet without result. SOME GENERAL CONCLUSIONS- 289 It is important that general truths of this kind, impressed upon us by our descent to the ascer- tained beginnings of life, should be generally known, as counteractive to the confident statements so frequently put forth by enthusiastic speculators and caterers of sensational popular science. In point of fact, we still occupy the position so long ago defined by the Apostle Paul, that " God's invisible things from the creation of the world are clearly seen, being understood by the things that are made, even His eternal power and divinity ; " and the rational student of nature must still be a pupil in the school of the Almighty Maker of all things. Realizing this, we can learn something both £is to the dignity and the humility of our own posi- tion. On the one hand we perceive that, in the whole chain of life, man is the only being in the likeness of the Maker, fitted to be His deputy in the world, to understand His great work, and to be the heir of the whole. To man alone He has pro- claimed, " I have said ye are gods, and all of you children of the Most High." To man alone has He given that " inspiration of the Almighty " which makes Him the interpreter of nature. On the other hand, when we consider the long extent in time of 19 290 RELICS OF PRIMEVAL LIFE the great chain of Hfe before man, and along with this the vast oceanic area inaccessible to us, yet ever since the dawn of life teeming with living things innumerable, we find that man is not even in this little world the only object of Divine care, and we learn a lesson of humility and of the obliga- tions which rest on us not only in relation to our fellow-men, but toward our humbler companions who share with us the care of their Father and ours. Finally, it is plain that scientific investigation can never bring us within reach of the absolute origin of life, otherwise than by the action of a creative Will. Had we stood on the earliest shore, and had we seen living things appear in the waters where before had been merely inorganic sand or rock, we should have known as little as we know to-day of even the proximate causes of this new departure in nature. If agnostics, we might have said, " this is spontaneous generation " ; but such an expres- sion would convey no distinct idea of the nature of the change which had occurred. It would be merely a cloak for- our ignorance. If theists, we might say, " this is creation " ; but we would have heard no audible fiat, nor seen any process or SOME GENERAL CONCLUSIONS 2Q1 manipulation, nor known by what subordinate agency, if any, the result was produced. We could have given no further explanation than that of the ancient writer who tells us that God said, " Let the waters swarm with swarmers." We are told that when these great creative changes occurred, they were witnessed by higher intelligences than man. " Then the morning stars sang together, and all the sons of God shouted for joy " ' ; but even they could perhaps know little more than we, though they might be better able to trace the future de- velopment of the wonderful plan commenced in the humble Protozoa and culminating in man and im- mortality. ' Job xxxviii. 7. APPENDIX 1(8 APPENDIX A. Geological Relations of Eozoon, Arch^ozoon, etc. T N the text I have given the arrangement of the pre-Cambrian rock-formations of Canada, as understood by me at the time of the delivery of the lectures on which this work is based — an arrangement which I believe will, in the main, be sustained by the work of the future, but which cannot as yet be received as final. The work of Logan and Murray, so far as I have had opportunity to go over their ground, was admirable ; but since their time the progress in the settlement of the country, the ex- tension of railways, and other means of communi- cation, and the opening up of mineral deposits have greatly increased the means of obtaining information, and detailed explorations have been in progress under the Geological Survey of Canada. At this moment, under the new Director of the Survey, Dr. G. M. Dawson, much work is being done in this 296 APPENDIX difficult field, more especially by Dr. Ells, Dr. Adams, and Mr. Barlow, which it may be hoped will go far to settle finally the arrangement and distribution of pre-Cambrian rocks in the Northern part of the American Continent. The maps and detailed reports representing these explorations are not yet before the public, but from some preliminary notices which have appeared in scientific periodicals, it may be inferred that the distinction between the fundamental gneiss, with its associated igneous pro- ducts, and the Upper Laurentian, will become greater than was supposed by Logan. The Lo^yest Laurentian or Trembling Mountain series of Logan now represents a very widely extended basement formation, not so far as can be ascertained, com- posed of sedimentary rocks in a metamorphosed state, but rather of peculiar aqueo-igneous materials, different from the greater part of those which succeeded them, and associated with varied and extensive igneous intrusions and in-vieltings like those which Keilhau ascertained long ago in the case of similar rocks in Norway. The Grenville series, on the other hand, may prove to be a remnant of an overlying system, originally less extensive or bordering the older group, and greatly i><<>Ti Fig. 6o. — Eozoon Canadense, Portion of a large specimen. Nature-printed. Showing the laminae, and irregular cavities filled with serpentine, perhaps corresponding to the funnels. APPENDIX 297 attenuated by the enormous denudation which the whole region has undergone. It may also be found that the beds of limestone are fewer and their repetitions more numerous than had been supposed, and that the Grenville series may be closely associ- ated locally, at least, with beds hitherto of uncertain age, or associated with the Lower Huronian. The Huronian proper, on the other hand, may be con- siderably extended, and the Kewenian and Animikd series overlying it have already been ascertained by the Canadian Geological Survey to overlap the Huronian and Laurentian over vast areas between the great lakes and the Arctic sea, evidencing much submergence at the close of the Huronian age, and opening of the Palaeozoic. I have noticed in the text the apparently wide development of deposits of this age over the area of the Rocky Mountains of Canada, and the corresponding territories in the United States. There would seem to be in these regions a great thickness' of unaltered sediments between the Lower Cambrian and the crystalline rocks below, representing the Huronian and Lau- rentian. In these very few fossils have yet been found, but they afford perhaps the most promising field, next to their representatives in Newfoundland 298 APPENDIX and New Brunswick, for the discovery of the pre- decessors of the Olenellus fauna, and the forms of life connecting these with those known in the Huronian and Laurentian. [For summaries of facts on the last-mentioned subject, see Report of Dr. G. M. Dawson on the Kamloops map-sheet, in "Reports of Geological Survey of Canada," vol. vii. B, new series, pp. 29 et seq. ; also Reports of Dr. C. D. Walcott, U. S. Geological Survey, vol. xiv., Part I., pp. 103 et seq., and Part II., pp. 503 et seq.] B. Preservation of Organic Remains by Injection with Hydrous Silicates. The late Dr. T. Sterry Hunt contributed to the original paper on Eozoon in the Journal of the Geological Society, a valuable essay on the minerali- zation of fossils by serpentine, glauconite, and allied hydrous silicates. This was in part reprinted in the notes appended to one of the chapters of "The Dawn of Life," and the subject was further discussed by Hunt in his invaluable work, " Chemi- cal and Geological Essays," and more especially in the chapter on the " Origin of Crystalline Rocks," a APPENDIX 299 chapter which every geologist deserving the name should study with care. I give here some of the more important facts referred to by Hunt, and may add that subsequent microscopic studies have familiarized me with the occurrence of serpentine and other hydrous silicates as fillings of the cavities of fossils of various geo- logical ages, insomuch that I have come to regard the occurrence of these rocks in association with fossiliferous limestones as among the best available means to enable us to ascertain the minute struc- tures of shells, Foraminifera, corals, etc. The following remarks and analyses further illus- trate Hunt's views on the relations of these minerals, with some of the facts on which they are based : — " In connection with the Eozoon it is interesting to examine more carefully into the nature of the matters which have been called glauconite or green- sand. These names have been given to substances of unlike composition, which, however, occur under similar conditions, and appear to be chemical de- posits from water, filling cavities in minute fossils, or forming grains in sedimentary rocks of various ages. Although greenish in colour, and soft and earthy in texture, it will be seen that the various 30O APPENDIX glauconites differ widely in composition. The variety best known, and commonly regarded as the type of the glauconites, is that found in the green- sand of Cretaceous age in New Jersey, and in the Tertiary of Alabama ; the glauconite from the Lower Silurian rocks of the Upper Mississippi is identical with it in composition. Analysis shows these glauconites to be essentially hy'drous silicates of protoxyd of iron, with more or less alumina, and sm^ll but variable quantities of magnesia, besides a notable amount of potash. This alkali is, however, sometimes wanting, as appears from the analysis of a green-sand from Kent, in England, by that care- ful chemist, the late Dr. Edward Turner, and in another examined by Berthier, from the calcaire grassier, near Paris, which is essentially a serpentine in composition, being a hydrous silicate of magnesia and protoxyd of iron. A comparison of these last two will show that the loganite, which fills the ancient Foraminifer of Burgess, is a silicate nearly related in composition. I. Green-sand from the calcaire grassier, near Paris. Berthier (cited by Beudant, " Mineralogie," ii., i;8). II. Green-sand from Kent, England. Dr. Edward APPENDIX 301 Turner (cited by Rogers, Final Report, Geol. N. Jersey, page 206). III. Loganite from the Eozoon of Burgess. IV. Green-sand, Lower Silurian ; Red Bird, Min- nesota. V. Green-sand, Cretaceous, New Jersey. VI. Green-sand, Lower Silurian, Orleans Island. The last four analyses are by myself." I. 11. III. IV. V. VI. Silica 4o"o 48-5 3S'i4 46-58 50-70 50-7 Protoxyd of iron 247 22 -Q 860 2o-6i 22-50 8-6 Magnesia . 1 6-6 3-8 31-47 1-27 2-16 37 Lime 3-3 2-49 i-ii Alumina . . 17 17-0 io'i5 II -45 8-03 19-8 Potash . traces 6-96 5-80 8-2 Soda -98 75 ■5 Water . 12-6 7-0 14-64 966 8-95 8-5 98-9 98-3 lOO-QO lOOOO lOQ-OO lOO-Q An eminent example is the Silurian limestone of Pole Hill, in New Brunswick, collected by the late Mr. Robb, of the Geological Survey, and referred to in the text. I cannot doubt that the silicate injecting Crinoids and other fossils in this limestone must have been introduced into these when still recent, and the same remark applies to the serpen- 302 APPENDIX tine filling a coral at Lake Chebogamong, and frag- ments of corals at Melbourne, in Eastern Canada, and to the similar mineral filling fossils in a limestone from Llangwyllog, in Wales, and in that of Maxville, Ohio. Hunt regarded all these as coming essentially into the same category as regard to general composition and properties. His analysis of the minerals from Pole Hill and Llangwyllog is as follows : — Pole Hill Llangwyllog Silica . . . 38-93 . . . 35'33 Alumina . . . 28-88 . 22-66 Protoxyd of iron I8-86- . 24'12 Magnesia. 4-25 . . . . 696 Potash . . • 1-69 .1-40 Soda •48. . . . . 0-67. Water . 6-91 . 11-46 Insoluble, quartz lOQ-OO 9989 These minerals approach in composition to the jollyte of Von Kobell, from which they differ in con- taining a portion of alkalies, and only one half as much water. In these respects they agree nearly with the silicate found by Robert Hoffman, at Raspenau, in Bohemia, where it occurs in thin layers alternating with picrosmine, and surrounding APPENDIX 303 masses of Eozoon in the Laurentian limestones of that region ; * the Eozoon itself being there injected with a hydrous silicate which may be described as intermediate between glauconite and chlorite in composition." In the Welsh specimen the silicate is of a deep green colour, except where oxidized, and though only 3 per cent, of the whole, is sufficient to give it an olive colour and slight serpen tinous lustre. In the Pole Hill material, the silicate amounts to 5 per cent, of the whole, and is of a greyish colour. For some further particulars, see my Paper on " Fossils Mineralized with Silicates " {Journal Geo- logical Society, February, 1879). C Affinities of Eozoon, etc., with MORE Modern Forms. Dr. Carpenter, who in admirable papers, which I need not quote here,* hcis illustrated in detail the • Joum. fur Prakt. Chemie, Bd., 106 (1869), p. 356. ' I may specially refer to the following : — W. B. Carpenter on Eozoon Canadense. Intellectual Observer, No. xl., p. 300, 1865. Supplemental notes on the 304 APPENDIX structures of Eozoon, and shown its resemblance to modern forms, places Eozoon as a generalized type between the Nummuline and Rotaline groups of Foraminifera. It resembles the former in its fine and complicated tubulations, and some of the larger sessile forms of the latter in its habit of growth. More especially, this is near to that of the genera Carpenteria and Polytrema. In the former, more especially, there are a number of somewhat flattened calcareous cells with perforated walls, and built up in a conical form around a central pipe or funnel into which the apertures of the cells open. A specimen of Carpenteria, enlarged structure and affinities of Eozoon Canadense, Quart. Journ. Geol. Sac, Lond. Vol. xxii., pp. 219-228, 1866. Notes on the structures and affinities of Eozoon Canadense. Canad. Nat., new ser., vol. ii., pp. 111-119, wood-cut, 1865. A reprint from Quart. Journ. Geol. Soc, Lond., 1865. Further obser- vations on the structure and affinities of Eozoon Canadense. In a letter to the President. Proc. Roy. Soc., Lond., vol. xxv., pp. 503-508, 1867. New observations on Eozoon Canadense. Ann. and Mag. Nat. Hist., ser. 4, vol. xiii., pp. 456-470, one plate, 1874. Final note on Eozoon Canadense. Ann. and Mag. Nat. Hist., ser. 4, vol. xiv., pp. yj^-JiT^; 1874. Remarks on Mr. H. J. Carter's letter to Prof. King on the structure of the so-called Eozoon Canadense. Ann. and Mag. Nat. Hist., ser. 4, vol. xiii., pp. 277-284, with two engravings, 1874. APPENDIX 305 and having the walls of its cells thickened by a supplemental tubulated deposit like that of Calcar- ina, would approach very near to Eozoon. The question of the general relation of an organ- ism like Eozoon to creatures known to us in the modern seas may be answered in either of two ways : — (i) Functionally or in relation to the posi- tion of such an animal in nature : or (2) Zoologi- cally, or with reference to its affinities to other animals. With reference to the first consideration, the answer is plain. The geological function of Eozoon was that of a collector of calcareous matter from the surrounding waters, then probably very rich in calcium carbonate, and its role was the same with that of the Stromatoporas and calcareous Sponges, smaller Foraminifera and Corals in latter times. The answer to the second aspect of the question is less easy. An ordinary observer would at once place Eozoon with the Stromatoporidae or Layer-corals, which fill or even constitute whole beds of limestone in the Cambro-Silurian, Silurian and Devonian Periods. While, however, Eozoon has been claimed on the highest authority for the Rhizopods, the Stromatoporse and their allies have been regarded as Sponges, or more recently as 20 306 APPENDIX Hydroids allied to the Hydractinise and Millepores.^ I confess that I am not satisfied with these inter- pretations. I have in my collections large numbers of encrusting spinous forms, usually called Stroma- toporae, but which I have long set aside as probably Hydractinise. There are other forms with large vertical tubes which I have regarded as corals, but some Stromatoporae seem to be different from either, and I am still disposed to regard many of them as Protozoa. Bearing in mind, however, that the Silurian is £is remote from the Laurentian on the one hand as from the Tertiary on the other, we might be prepared to expect that if the Layer-corals of the Silurian are divisible into different groups, somewhat widely separated, and we have in the lower Palaeozoic the peculiar type of Cryptozoon, we may be prepared to expect in the Laurentian much more generalized forms, less susceptible of classification in our modern systems. If, therefore, Eozoon were accessible to us in a living state, I should not be surprised to find that — while perhaps more akin to the calcareous-shelled Rhizopods than to any other modern group — it may have presented ' See Nicholson and Murie's able memoirs, Publications of Pal. Soc, 1885. APPENDIX 307 points of resemblance to Sponges or even to Hydroids, in its skeleton and mode of growth, and even in the arrangement of its soft parts. Taking this view of its nature and relations, the genus and the Laurentian species may be charac- terized as follows : — Genus EOZOON, Dawson. Foraminiferal skeletons, with irregular and often confluent cells, arranged in concentric and horizon- tal laminae, or sometimes piled in an acervuline man- ner. Septal orifices irregularly disposed. Proper wall finely tubulated. Intermediate skeleton with branching canals. EozooN Canadense, Dawson. In inverted conical or rounded masses or thick encrusting sheets, frequently of large dimensions. Typical structure stromatoporoid, or with concentric calcareous walls, frequently uniting with each other, and separating flat chambers, more or less mam- millated, and spreading into horizontal lobes and small chamberlets ; chambers often confluent and crossed by irregular calcareous pillars connecting the opposite walls. Upper part often composed of acervuline chambers of rounded forms. Proper wall J08 APPENDIX tubulated very finely. Intermediate skeleton largely developed, especially at the lower part, and traversed by large branching canals, often with smaller canals in their interstices. Lower laminae and chambers often three millimetres in thickness. Upper laminae and chambers one millimetre or less. Age Upper Laurentian and perhaps Huronian. Var. MINOR. — Supplemental skeleton wanting, except near the base, and with very fine canals. Laminae of sarcode much mammillated, thin, and separated by very thin walls. Probably a depauper- ated variety. Var. ACERVULINA. — In oval or rounded masses, wholly acervuline. Cells rounded ; intermediate skeleton absent or much reduced ; cell-walls tubu- lated. This may be a distinct species, but it closely resembles the acervuline parts of the ordinary form. Assuming the Archaeospherinae so abundantly found in the Eozoon limestones to be distinct organisms, and not mere germs or buds of Eozoon, they may be thus defined : — Genus ArcH/EOSPHERina, Dawson. A provisional genus, to include rounded solitary chambers, or globigerine assemblages of such cham- APPENDIX 309 bers, with the cell-wall surrounding them tubulated as in Eozoon, or perhaps in some cases with simple pores like those of Rotalines. They may be dis- tinct organisms, or gemmae, or detached fragments of Eozoon. Some of them much resemble the bodies figured by Dr. Carpenter, as gemmae or ova and primitive chambers of Orbitolites. They are very abundant on some of the strata surfaces of the limestones at C6te St. Pierre. Age Upper Lauren- tian. I may add here the characters of Matthew's new genus, Archseozoon, as given by him : — Genus Arch^ozoON, Matthew. Skeleton composed of thin concentric laminae convex upward, and having between them a granu- lar layer filled with minute branching canals. Arch^ozoon Acadiense, Matthew. Habit of growth cylindrical in masses or groups, budding upward. The microscopic characters are thus given by Matthew : ' — " The structures appear to be allied more closely to Cryptozoon than to Eozoon. The microscopic ' Bulletin No. ix., Nat. Hist. Soc. of New Brunswick, 1890. 3 16 APPENDIX structure is most easily recognised in the earthy (as distinguished from the calcareous) layers, and consists of minute branching canals. Under a one- inch objective the smaller canals have the appear- ance of minute threads, which run sometimes for a distance of two millimetres without branching. The larger canals branch more frequently and are more sinuous. The canals cross and anastomose with each other; they run chiefly at right angles to the axis of the fossil, and appear to branch most in going outward from the centre. More rarely they ascend from the earthy to the calcareous layer, branching upward." In limestone of the Upper Laurentian, near St. John, New Brunswick. D. Cryptozoon. The description above given of Archaeozoon very naturally leads us to consider the allied Cambrian and pre-Cambrian forms known as Cryptozoon. This remarkable and problematical type was first described by Prof. James Hall in the Appendix to his Annual Report of 1882 (No. 26). It is a large massive organism, occurring abundantly on the sur- Appendix iii face of a limestone of Calciferous (Upper Cambrian) age at Greenfield, Saratoga County, New York. The individuals sometimes attain a diameter of two feet, and are often surrounded by smaller speci- mens apparently budding off from them. Like Stromatoporae, they consist of concentric laminae, but these are concave upward, giving a bowl-shaped form to the summits of the individuals. Prof Hall describes them as " made up of irregular concentric laminae of greater or less density, and of very un- equal thickness. The substance between the con- centric lines in well-preserved specimens is traversed by numerous minute irregular canaliculi which branch and anastomose without regularity. The central portion of the masses is usually filled with crystalline granular and Oolitic material, and many specimens show the intrusion of these extraneous and inorganic substances between the laminae." Professor Hall having kindly presented some good specimens to the Peter Redpath Museum, I have had sections made, and have thus been able to verify his description, and to compare the struc- tures with those of some of the more ancient Stromatoporoid specimens in our collections, in- cluding the Archaeozoon from New Brunswick, of 313 APPENDIX which Mr. Matthew has presented a fine slab to the Museum. I have also, through the kindness of Professor Winchell, been enabled to compare these with his Cryptozoon Minnesotense, and Dr. Walcott has added specimens of his Stromatoporoid forms from the pre-Cambrian beds of Arizona. It would appear from these and other specimens in our collections from the Cambrian and older Ordovician beds, that we have here an ancient type of Stromatoporoid organism in which the original laminae seem to have been thin and coriaceous, without apparent pores or pillars connecting them with each other, but having between them relatively thick layers of fine fragmental matter penetrated by numerous irregularly tortuous and branching tubes. The laminae often present a carbonaceous or chitinous appearance, though frequently replaced by mineral matter, and the intervening layers show both a calcareous and carbonaceous substance, with much fine silicious sand often as rounded grains, and apparently some dolomitic granules. The tubules seem destitute of any distinct wall, other- wise the whole would resemble on a large scale the nodular and laminated masses of Girvanella, which Wethered has described as surrounding organic APPENDIX 313 fragments in Silurian and Carboniferous and Jurassic limestones in England.^ The Streptochetus of Seely from the Chazy lime- stone^ is evidently very near to Girvanella, if not generically identical, and I have a similar species from the Lower Cambrian pebbles in the con- glomerates of the Quebec group. In all these forms, however, the thicker or intermediate laminae seem to consist wholly of definite convoluted tubes, whereas in Cryptozoon the tubes, or tubular per- forations, are separated by a mass of material which in the best preserved specimens seems to consist of a fibrous stroma including calcareous and silicious particles. It seems doubtful to what class of beings such a structure should be referred ; but whatever its nature, it evidently had great powers of growth, and seems to be a very ancient form of life. One of the species similar in structure to Hall's type, but budding out into turbinate branches, was discovered by Mr. E. T. Chambers, of Montreal, in the Ordovician limestone of Lake St. John, and has been named C. boreale. It differs in structure from Hall's species in having the tubes less tortuous 1 British Association, Liverpool nneeting, 1896. ^ Amer. Journ. of Science, 1885. See Nicholson, "Manual of Palseontology," ed. of 1889. 3l4 APPENDIX and more nearly parallel to the laminae. In its outline it reminds one of the problematical Eozoon from the Hastings group at Tudor, Ontario, referred to in the text. Should time permit, I hope to have all the speci- mens in our collections illustrating this interesting and primitive type examined and described. In the meantime I may merely remark that a near modern analogue would seem to be the gigantic arenaceous Foraminifer Neusina Agassizi, Goes, dredged by Alexander Agassiz in the Pacific, and described in the Bulletin of the Museum of Com- parative Zoology (Vol. xxiii., No. 5, 1892). The modern form, it is true, is flat and foliaceous ; but some of the old species approach to this shape, and if we suppose the little cells of Neusina to represent the tubes of Cryptozoon, and the carbonaceous matter of the latter to be the remains of the chitinous stroma seen in some specimens, the general resemblance will be very close. The whole subject of these peculiar Stromato- poroid forms extending from the Upper Cambrian to the Laurentian, deserves a full and careful investigation, for which I am endeavouring to collect material. APPENDIX 315 E. Receptaculites and Arch^ocyathus. In "The Dawn of Life" (1875), reference was made to the singular and complicated organisms of the Upper Cambrian and Ordovician systems known as Receptaculites, which at that time was generally regarded as foraminiferal, and is still placed by Zittel, in his great work on Palaeontology, among forms doubtfully referable to that group. It has also been referred to Sponges, though on very uncertain grounds. It has not, however, so far as I am informed, been traced any farther back than the Upper Cambrian (Calciferous), and no structural links are known to connect it with either Eozoon or Archaeozoon. For this reason it was omitted in the text ; but I think it well to mention it here, and to direct attention to it as possibly one of the complex Protozoa which may be traced far back toward the beginnings of life.^ Another primitive and generalized genus men- tioned in the text is Archceocyathus of Billings, whose headquarters seem to be in the Lower Cam- brian, and which may probably be traced farther back. Billings, " Pateozoic Times." 3l6 APPENDIX Mr. Billings described the genus in his "Report on Canadian Fossils" (1861-64), taking A. profundus, from the Lower Cambrian of L'Anse ^ Loup, on the Labrador coast, in the first instance, as the type. A few years later, my attention was attracted to this species by specimens presented to me by Mr. Carpenter, a missionary on the Labrador coast, and which Mr. Billings kindly permitted me to compare with his specimens in the Museum of the Geologi- cal Survey, collected by the late Mr. Richardson, at L'Anse k Loup, in Labrador, in what were then called Lower Potsdam rocks. Slices of the speci- mens were made for the microscope, when it appeared that, though they had the general aspect of turbinate corals, like Petraia, etc., they were quite dissimilar in structure, more especially in their porous outer and inner walls and septa (see Fig. 5, P- 3S)- Yet they could scarcely be referred to the group of porous corals known in much later forma- tions and in the modern seas. Nor could they be referred with much probability to Sponges, as they were composed of solid calcareous plates, which, as was evident from their textures, could not have been originally spicular. One seemed thus shut up to the conclusion that their nearest alliance was with APPENDIX 317 Foraminifera, and if so, they were very large and complex forms of that group, consisting of perfor- ated chambers arranged around a central cavity. I accordingly mentioned them in this connection in 1875, not as closely related to Eozoon, but as apparently showing the existence of very complex foraminiferal forms in the Lower Cambrian. The specimens thus noticed were altogether cal- careous, and were of the species named A. profundus by Mr. Billings. He had, however, referred to the same genus silicified specimens from a later forma- tion, the Calciferous (Upper Cambrian) at Mingan, under the name A. Minganensis, which were subsequently found to be associated with spicules resembling those of lithistid sponges, and which proved to be very different from the Lower Cam- brian form, and are now referred to a different genus. The subject had thus become involved in some confusion, and was left in this state by Mr. Billings on his death. I therefore asked my friend. Dr. Hinde, of London, to re-examine my specimens, and at the same time those of the Geological Survey were placed in his hands by Mr. Whiteaves. Hinde also obtained specimens from Lower Cambrian rocks in Sardinia, where they seem to be abundant, and 3l8 APPENDIX from Spain. He states the results of his examina- tions very fully in a paper in the Journal of the Geological Society of London} He retains the origi- nal name for the older and calcareous form from L'Anse a Loup, separating from it, however, another form, A. Atlanticus of Billings's, which is destitute of distinct radiating septa and acervuline, like the lower part of A. profundus. This he names Spirocyathus. The Mingan species he places with Sponges under the generic name, Archceoscyphia. In this Walcott sub- stantially agrees with Hinde in his " Memoir on the Lower Cambrian Fauna." Both seem to refer Archseocyathus to corals, though admitting its very exceptional and anomalous structure. I think, how- ever, we may still be allowed to entertain some doubts as to the reference to corals, more especially as the skeleton does not seem to have consisted of aragonite, but of ordinary calcite, like that of the Foraminifera. It is in any case a primitive form which seems to be dying out in the Lower Cambrian, and we may hope that it may be traced into the pre-Cambrian, and may form a link connecting the Palaeozoic with the Eozoic faunas. In my description of it in " The ' Vol. xlv., 1889, pp. 125 etseq. APPENDIX 319 Dawn of Life" in 1875, I used the following terms : — " To understand Archaeocyathus, let us imagine an inverted cone of carbonate of lime from an inch or two to a foot in length, with its point planted in the mud in the bottom of the sea, while its open cup extends upward into the clear water. The lower part buried in the bottom is composed of an irregular network of thick calcareous plates, enclosing chambers communicating with one another. Above this, where the cup expands, its walls are made up of inner and outer plates, perforated with numerous round pores in vertical rows, and con- nected with each other by vertical partitions also perforated, so as to establish a free communication of the enclosed radiating chambers with each other, as well as with the water within and without. Such a structure might no doubt serve as a skeleton for a coral of somewhat peculiar internal structure, but it might just as well accommodate a protozoan with chambers for its sarcode, and pores for emission of pseudopods, both outwardly and by means of the interior cup, which in that case would represent a funnel like that of Carpenteria, or one of the tubes of Eozoon." On the whole, when we consider the magnitude 329 APPENDIX and synthetic character of such forms as Cryptozoon, Receptaculites, and Archaeocyathus, and their associ- ation with generalized types of Crustaceans and Brachiopods, we can scarcely fail to perceive that at the base of the Palaeozoic we are leaving the reign of the higher marine invertebrates, and enter- - ing on a domain where lower and probably Proto- zoan forms must be dominant, and so are getting at least within calculable distance of the beginnings of life. F. Pre-Geological Evolution, Reference is incidentally made in the text to the doctrine implied in the old notion of successive cataclysms and renewals of the earth, held by some ancient mythologies and philosophies, and revived in a slightly different form by Mr. Herbert Spencer, in connection with the requirements of the Darwinian evolution by natural selection. This primitive idea was illustrated at considerable length by Professor Poulton in his address as President of the Zoological Section of the British Association at its meeting in Liverpool (September, 1896). In this new and ably presented form, it deserves some notice APPENDIX 321 as excluding the hope of our finding the beginnings of life in any geological formations at present known. Professor Poulton refers to the argument used by Lord Salisbury, in his address at the Oxford meeting, on the insufficiency of time for the require- ments of the Darwinian evolution. He then dis- cusses the estimates based by Lord Kelvin and Professor Tait on physical considerations, and dismisses them as altogether inadequate, though he admits that Professor George Darwin agrees with Lord Kelvin in regarding 500 millions of years as the maximum duration of the life of the sun. He next takes up the estimates of geologists, and rather blames as too modest those who ask for the longest time, say 400 millions of years, for the duration of the habitable earth. He evidently scarcely deems worthy of notice the more moderate demands of many eminent students of the earth, who have based far lower estimates on more or less reliable data of denudation and deposition, and on the thickness of deposits in connection with their probable geographical extent. He then proceeds to consider the biological evi- dence, and dwells on the number of distinct types 21 322 APPENDIX represented as far back as the Lower Cambrian. Independently of the interpretations and explana- tions of this great fact, the numerous types there represented, and the persistence of some of them to the present day, give an almost overwhelming impression of the vast duration of organisms in time. In connection with the supposed slow and gradual process of evolution, this naturally leads to the conclusion that " the whole period in which the fossiliferous rocks were laid down must be multi- plied several times for this later history (that of the higher groups of animals alone). The period thus obtained requires to be again increased, and perhaps doubled for the earlier history." Ordinary geologists naturally stand aghast at such demands, and inquire if they are seriously put forth, and if it would not be wise to hesitate before accepting a theory on behalf of which such drafts on time must be made. The late Edward Forbes once humorously defined a geologist to be "an amiable enthusiast who is happy and content if you will give him any quantity of that which other men least value, namely, past time." But had this great naturalist lived to " post-Darwinian " times, he might have defined a Darwinian biologist to be an insatiable APPENDIX 323 enthusiast, who feels himself aggrieved if not sup- plied with infinity itself, wherein to carry on the processes of his science. Seriously however, the necessity for indefinitely protracted time does not arise from the facts, but from the attempt to ex- plain the facts without any adequate cause, and to appeal to an infinite series of chance interactions apart from a designed plan, and without regard to the consideration, that we know of no way in which, with any conceivable amount of time, the first living and organized beings could be spontaneously produced from dead matter. It is this last difficulty which really blocks the way, and leads to the wish to protract indefinitely an imaginary process, which must end at last in an insuperable difficulty. Were Evolutionists content to require a reason- able time for the development of life, and to assign this to an adequate cause, they might see in the reduction of living things in the pre-Cambrian ages to few and generalized or synthetic types, evidence of an actual approach to the beginnings of life, and beyond this to a condition of the earth in which life would be impossible. 324 APPENDIX G. Controversies Respecting Eozoon. In the text (Chapter IX.) I have referred in a cursory manner to these, but have felt that it would be unprofitable to fight the old battles over again, except in so far as the objections raised have suggested new lines of study and investigation. The old objections of Messrs. Rowney, King and Carter were conclusively replied to by the late Dr. Carpenter. The later criticisms of Mobius in his elaborated memoir in "Palseontographica" were in appearance more formidable ; but he had evidently entered on the question with imperfect material, and a very defective conception of its extent and mean- ing. His treatment of it was also marked by unfairness to those who had previously worked at the subject, and by that narrow specialism and captious spirit for which German naturalists are too deservedly celebrated. The difficulties he raised were met at the time, more especially in articles by the present writer in the American Journal of Science, and in the Canadian Naturalist. Mobius, I have no doubt, did his best from his special and limited point of view ; but it was a crime which science should not readily pardon or forget, on the APPENDIX 325 part of editors of the German periodical, to publish and illustrate as scientific material a paper which was so very far from being either fair or adequate. The later objections of Gregory and Lavis are open to similar criticism as imperfect and partial, and as confounding Eozoon with mineral structures which previous writers had carefully distinguished from it. I have stated these points in letters to Nature and to the Council of the Dublin Academy, and have also re-stated the evidence bearing on the animal nature of Eozoon in a series of papers in the Geological Magazine for 1895. I may add here, as apposite to the present condition of the matter, a few remarks referring to the appearance of Eozoon in Dr. Dallinger's new edition of Carpenter's great work on the Microscope,* and more especially to his retaining unchanged the description of Eozoon CanadensCy as a monument of an important research up to a certain date, while adding a note with reference to the later criticisms of Mr. Gregory. Dr. Carpenter devoted much time to the study of Eozoon, and brought to bear on it his great experi- ence of foraminiferal forms, and his wonderful ' Nature, March 17, 1894. 326 APPENDIX powers of "manipulating and unravelling difficult structures. After having spent years in studying microscopic slices of Eozoon and the limestones in which it occurs, I have ever felt new astonishment when I saw the manner in which, by various pro- cesses of slicing and etching, and by dexterous management of light, he could bring out the struc- ture of specimens often very imperfect. Not long before Dr. Carpenter's death, I had an opportunity to appreciate this in spending a few days with him in studying his more recently acquired specimens, some of them from my own collections, and dis- cussing the new points which they exhibited, and which unhappily he did not live to publish. Some of these new facts, in so far as they related to speci- mens in our cabinet here, have since that time been noticed in my rhumi of the question in the "Memoirs of the Peter Redpath Museum," 1888. Those who know Dr. Carpenter's powers of investigation will not be astonished that later observers, without his previous preparation and rare insight, and often with only few and imperfect specimens, should have failed to appreciate his results. One is rather surprised that some of them have ventured to state with so great confidence APPENDIX I2f their own negative conclusions in a matter of so much difficulty, and requiring so much knowledge of organic structures in various states of minerali- zation. For myself, after working fifty years at the microscopic examination of fossils and organic rocks, I feel more strongly than ever the uncertainties and liabilities to error which beset such inquiries. As an illustration in the case of Eozoon : since the publication of my memoir of 1888, which I had intended to be final and exhaustive as to the main points in so far as I am concerned, I have had occasion to have prepared and to examine about 200 slices of Eozoon from new material ; and while most of these have either failed to show the minute structures or have presented nothing new, a few have exhibited certain parts in altogether un- expected perfection, and have shown a prevalence of injection of the canal system by dolomite not previously suspected. I have also observed that unsuitable modes of preparation, notably some of those employed in the preparation of ordinary petrological slices, may fail to disclose organic struc- tures in crystalline limestones when actually present. Since that publication also, the discoveries of Mr. Matthew in the Laurentian of New Brunswick, and 32§ APPENDIX the further study of the singular Cambrian forms of the type of Cryptozoon, have opened up new fields of inquiry. I think it proper to state, in reference to Dr. Dallinger's footnote on the recent paper of Mr. Gregory, that it must not be inferred from it that Mr. Gregory had access to my specimens from Madoc and Tudor, though he no doubt had excel- lent material from the collections of the Canadian Geological Survey. It might also be inferred from this note that I have regarded the Madoc and Tudor specimens as " Lower Laurentian." The fact is, that I was originally induced in 1865, by the belief of Sir W. E. Logan at that time that these rocks were representatives in a less altered state of the middle part of the Laurentian, to spend some time at Madoc and its vicinity in searching for fossils, but discovered only worm-burrows, spicules, and fragments of Eozoon, which were noticed in the Journal of the Geological Society for 1866. (The more complete specimen from Tudor was found by Vennor in 1866.) On that occasion I satisfied myself fully that the beds are much older than the Cambro-Silurian strata resting on them, unconformably ; but I felt disposed to regard them APPENDIX 329 as more probably of the age of some parts of the Huronian of Georgian Bay, which I had explored with a similar purpose under Logan's guidance in 1856. [In my subsequent notice of the Tudor specimens in "The Dawn of Life," in 1875, I referred to their age as " Upper Lauren tian or Huronian " ; and I may add, that while it is certain that the beds containing them are pre-Palaeozoic, their place in the Eozoic period is still not precisely determined. Work is, however, now in progress which it is hoped may finally settle the age of the " Hastings group" and the old rocks associated with it. I may add that the specimen of Cryptozoon discovered by Mr. Chambers, and of which a portion is repre- sented in the Frontispiece, seems to me to throw a new light on the Tudor specimen. It shows in any case the survival of Cryptozoa similar in form and general appearance to that specimen, as late as the Cambro-Silurian or Ordovician.] H. Notes to Appendix, December, 1896. While this work was going through the press, I have received the Report of the U.S. Geological 330 APPENDIX Survey for 1894-95, containing the elaborate Memoir of C. R. Van Hise on the pre-Carabrian Geology of North America, It is a very valuable contribution to the literature of this difficult subject, and will con- stitute a standard book of reference : though I think the use of the term " Algonkian " for groups of beds which are in part basal Palaeozoic and in part Eozoic or Archaean is to be deprecated, and scarcely suffi- cient importance is attached to the labours of the early Canadian explorers in this field. In the past summer I was enabled to spend a few days, with the assistance of my friend Mr. H. Tweed- dale Atkin, of Egerton Park, Rock Ferry, in examin- ing the supposed pre-Cambrian rocks of Holyhead Island and Anglesey. Fossils are very rare in these beds. As Sir A. Geikie has shown, the quartzite of Holyhead is in some places perforated with cylindri- cal worm-burrows, and in the micaceous shales there are long cylindrical cords, which may be algae of the genus Palceockorda, and also bifurcating fronds re- sembling Chondrites ; but I saw no animal fossils. I have so far been unable to discover organic structure in the layers of limestone associated with apparently bedded serpentine in the southern part of Holyhead Island. In central Anglesey there are lenticular APPENDIX 331 beds of limestone and dolomite associated with pre- Cambrian rocks, which Dr. Callaway regards as pro- bably equivalent to the Pebidian of Hicks. In these there are obscure traces of organic fragments ; and in one bed near Bodwrog Church I found a rounded laminated body, which may be an imperfectly pre- served specimen of Cryptozoon, or some allied or- ganism. The specimens collected have not, however, been -yet thoroughly examined. These and other pre-Cambrian deposits in Great Britain correspond in their testimony, with the Eozoic rocks of North America, as to the small number and rarity of fossil remains in the formations below the base of the Palaeozoic, and the consequent probability that in these formations we are approaching to the beginning of life on our planet ;' though there is still reason to hope that additional oases of life may be found in these deserts of the pre-Palaeozoic. Such rare inter- vals of fertility should be, the more valued when the labours of so many skilled observers have proved so meagre in their results in comparison with the great extent and thickness of the beds which have been explored. INDEX Adams on composition of Laurentian schists his work on Laurentian stratigraphy . Animals, Cambrian, classes of pre-Cambrian . Huronian . . . Grenvillian , . Antiquity, relative Aquatic animals, permanence of Aragonite in fossils . Archaeocyathus . Archasozoon Barlow, his explorations Bavaria, Eozoon of Beecher on limbs of Trilobites Bicknell on Eozoon . Billings on Eozoon on Receptaculites . on Archaeocyathus on Signal Hill fossils . Bonney on C6te St. Pierre . Burbank on Chelmsford Eozoon Calcarina .... Calumet, Grand, Eozoon of . io8 . 296 • 7, II • S3 . 67 73, 303 6 • 13 • 117 35,315 214, 309 296 71 25 141 137 315 316 54 143 141 186 130 INDEX 333 PAGE Canals of ^ozoqn . • I33 Cambrian, life of Early . 17 geography of the . 18 Carbon in ^Laurgntian limestone • 93 Carpenter,, Dr., on Eozoon 137, 303, 324 Cayeux on Huronian fossils . 68 Chambers, Mr. E. T. . • 313 Chrysotile, veins of . . . 161, 239 Coenostroma . 174 Colorado canon . . . . 56 Controversies respecting Eozoor . 324 Corals, history of . 32 C6te St. Pierre . . . 88, 91 Cryptozooh. . . 36, 56, 310 Dallinger, note on Eozoon . • 32s Dawson, Dr. G. M. . . 66, 295 Ells, Dr. , . . 217, 296 Eozoon, its discovery . • 73> 125 its general form . . 149 its mode of occurrence . 90 its state of preservation . Ill its laminae and chambers • 152, 157 its canals and tubuli . I 33, 138, 158, 160 its funnels . . 152 its minute granular structure • 133 its characters and affinities . 307 objections to its animal nature' . 221 acervuline specimens . . 203 in various places . 141, 233 Bavarian species . 71,213 Tudor specimen . 68 fragments of, in limestones . . 183 334 INDEX PAGE Eozoon, restoration of . . . . . . .327 Eozoic time as a geological age . . . 76 Etcheminian system . . . 48 fossils of . . . 54 Evolution, pre-geological . . 320 Foraminifera, notice of modern . . . 175 Etcheminian . . 59 Huronian . 71 Laurentian, etc. . . 303 Fossils, how mineralized . . Ill Glauconite, mineralizing fossils . 217, 298 Granular structure in Eozoon . . i6s Graphite of the Laurentian . 93 Gregory on Eozoon . . . 235. 32s Grenvillian series • 39 Gresley on Huronian worms . . 68 Giimbel on European Eozoon . 71.213 Hall, Dr. James, on Cryptozoon 36, 310 Hanford Brook, section at . . • SI Hastings series (Huronian ?) . 67 Hinde on Archaeocyathus . 34, 317 Hunt, Dr. Sterry, on indications of lif e • 97 on silicates in fossils . . 298 Huronian system . 65 Hymenocaris . 27 Jones, T. Rupert, on Eozoon 75. 137 Jullien on Eozoon . " . . , . 23s Kewenian or Kewenawan series . 48 King,' Prof., on Eozoon . 221 INDEX 335 FAGB Laurentian system « . • 7i its limestones 92 Lavis, Dr. Johnson, on Eozoon 235, 325 Life in Early Cambrian . . j . . . . 17 in pre-Cambrian 50 in Huronian . 65 in Laurentian , . 71 Limestones of Laurentian . 92 Logan, Sir W., on Eozoon 129 Loganite in Eozoon .128 Long Lake, Specimens from 190, 208 Lowe as explorer 131, 141 Map of Laurentian America 85 Grenville limestone 88 Matthew, Dr., on Archseozoon 214, 309 on Etcheminian 48, 51, 54 McMuUen as explorer 128 Mobius on Eozoon 161, 162 Murray on Signal Hill beds 53 Nummulite 163, 186 Objections , . 221 Ocean of Cambrian . • 18, 21 of Laurentian ........ 85 Olenellus zone ......... 20 Petite Nation 141 Pole Hill, specimen from 118 Pre-Cambriah life 47 Pre-Cambrian rocks in Canada 76 Pre-geological evolution 320 Pre-Palaeozoic life 216 Pyroxene in Eozoon 167, 169 336 INDEX PAGE Recep.taculites • '3^5 Robb, Pole Hill specimens 3°^ Serpentine, mineralizing fossils 147 different origins of 167, 171 Signal Hill series 53 Silicates, mineralizing fossils 217, 298 Spines, use of 3° Stromatoporse I73 St. Pierre, C6te 88, 91 Table of the history of life 2 of pre-Cambrian formations 76 Triarthrus 25 Tubuli of Eozoon 60, 61, 159 Van Hise on pre-Cambrian 66, 329 Varieties of Eozoon 107, 202 Vennor referred to 69 Walcott on Lower Cambrian 40, 62 on fossils, Colorado Canon 57 Weston, Mr., referred to ., 131 White, Prof C. A., on chronology of life .... 7 Wilson, Dr., referred to 127 Worm-burrows in Huronian 67 Worm-trails in Lower Cambrian, etc. ... 40, 43