Chapter I: II. III. IV. V. VI

Silica 40·0 48·5 35·14 46·58 50·70 50·7
Protoxyd of iron 24·7 22·0 8·60 20·61 22·50 8·6
Magnesia 16·6 3·8 31·47 1·27 2·16 3·7
Lime 3·3 2·49 1·11
Alumina 1·7 17·0 10·15 11·45 8·03 19·8
Potash traces 6·96 5·80 8·2
Soda ·98 ·75 ·5
Water 12·6 7·0 14·64 9·66 8·95 8·5
---- ---- ------ ----- ------ -----
98·9 98·3 100·00 100·00 100·00 100·0

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 serpentine filling a coral at Lake Chebogamong, and fragments 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 35·32
Alumina 28·88 22·66
Protoxyd of iron 18·86 } 24·12 }
Magnesia 4·25 } 6·96 }
Potash 1·69 } 1·40 }
Soda ·48 } 0·67 }
Water 6·91 11·46
Insoluble, quartz
------ -----
100·00 99·89

These minerals approach in composition to the jollyte of Von Kobell, from which they differ in containing 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 masses of Eozoon in the Laurentian limestones of that region;[51] the Eozoon itself being there injected with a hydrous silicate which may be described as intermediate between glauconite and chlorite in composition."

[Footnote 51: _Journ. fur Prakt. Chemie_, Bd., 106 (1869), p. 356.]

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 serpentinous 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 Geological Society_, February, 1879).

* * * * *

C. Affinities of Eozoon, etc., with more Modern Forms.

Dr. Carpenter, who in admirable papers, which I need not quote here,[52] has illustrated in detail the 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 and having the walls of its cells thickened by a supplemental tubulated deposit like that of Calcarina, would approach very near to Eozoon.

[Footnote 52: I may specially refer to the following:--

W. B. Carpenter on _Eozoon Canadense_. _Intellectual Observer_, No. xl., p. 300, 1865. Supplemental notes on the structure and affinities of _Eozoon Canadense_, _Quart. Journ. Geol. Soc._, 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 observations 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._, sen 4, vol. xiii., pp. 456-470, one plate, 1874. Final note on _Eozoon Canadense_. _Ann._ and _Mag. Nat. Hist._, ser. 4, vol. xiv., pp. 371-372, 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.]

The question of the general relation of an organism like Eozoon to creatures known to us in the modern seas may be answered in either of two ways:--(1) Functionally or in relation to the position of such an animal in nature: or (2) Zoologically, 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 Stromatoporæ 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 Stromatoporidæ 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 Stromatoporæ and their allies have been regarded as Sponges, or more recently as Hydroids allied to the Hydractiniæ and Millepores.[53] I confess that I am not satisfied with these interpretations. I have in my collections large numbers of encrusting spinous forms, usually called Stromatoporæ, but which I have long set aside as probably Hydractiniæ. There are other forms with large vertical tubes which I have regarded as corals, but some Stromatoporæ 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 as 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 Palæozoic 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 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.

[Footnote 53: See Nicholson and Murie's able memoirs, Publications of Pal. Soc, 1885.]

Taking this view of its nature and relations, the genus and the Laurentian species may be characterized as follows:--

_Genus_ Eozoon, _Dawson_.

Foraminiferal skeletons, with irregular and often confluent cells, arranged in concentric and horizontal laminæ, or sometimes piled in an acervuline manner. 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 mammillated, 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 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 laminæ and chambers often three millimetres in thickness. Upper laminæ 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. Laminæ of sarcode much mammillated, thin, and separated by very thin walls. Probably a depauperated variety.

_Var._ acervulina.--In oval or rounded masses, wholly acervuline. Cells rounded; intermediate skeleton absent or much reduced; cell-walls tubulated. This may be a distinct species, but it closely resembles the acervuline parts of the ordinary form.

Assuming the Archæospherinæ 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_ Archæospherina, _Dawson_.

A provisional genus, to include rounded solitary chambers, or globigerine assemblages of such chambers, 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 distinct organisms, or gemmæ, or detached fragments of Eozoon. Some of them much resemble the bodies figured by Dr. Carpenter, as gemmæ or ova and primitive chambers of Orbitolites. They are very abundant on some of the strata surfaces of the limestones at Côte St. Pierre. Age Upper Laurentian.

I may add here the characters of Matthew's new genus, Archæozoon, as given by him:--

_Genus_ Archæospherina, _Matthew_.

Skeleton composed of thin concentric laminæ convex upward, and having between them a granular layer filled with minute branching canals.

Archæospherina Acadiense, Matthew.

Habit of growth cylindrical in masses or groups, budding upward. The microscopic characters are thus given by Matthew[54]:--

"The structures appear to be allied more closely to Cryptozoon than to Eozoon. The microscopic 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 appearance 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."

[Footnote 54: Bulletin No. ix., Nat. Hist. Soc of New Brunswick, 1890.]

In limestone of the Upper Laurentian, near St. John, New Brunswick.

* * * * *

D. Cryptozoon.

The description above given of Archæozoon 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 surface 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 specimens apparently budding off from them. Like Stromatoporæ, they consist of concentric laminæ, 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 laminæ of greater or less density, and of very unequal thickness. The substance between the concentric 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 laminæ."

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 structures with those of some of the more ancient Stromatoporoid specimens in our collections, including the Archæozoon from New Brunswick, of 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 laminæ 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 laminæ 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, otherwise the whole would resemble on a large scale the nodular and laminated masses of _Girvanella_, which Wethered has described as surrounding organic fragments in Silurian and Carboniferous and Jurassic limestones in England.[55]

[Footnote 55: British Association, Liverpool meeting, 1896.]

The _Streptochetus_ of Seely from the Chazy limestone[56] is evidently very near to Girvanella, if not generically identical, and I have a similar species from the Lower Cambrian pebbles in the conglomerates of the Quebec group. In all these forms, however, the thicker or intermediate laminæ seem to consist wholly of definite convoluted tubes, whereas in Cryptozoon the tubes, or tubular perforations, 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.

[Footnote 56: _Amer. Journ. of Science_, 1885. See Nicholson, "Manual of Palæontology," ed. of 1889.]

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 and more nearly parallel to the laminæ. 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 specimens 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_, Goës, dredged by Alexander Agassiz in the Pacific, and described in the Bulletin of the Museum of Comparative 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 Stromatoporoid forms extending from the Upper Cambrian to the Laurentian, deserves a full and careful investigation, for which I am endeavouring to collect material.

* * * * *

E. Receptaculites and Archæocyathus.

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 Palæontology, 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 Archæozoon. 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.[57]

[Footnote 57: Billings, "Palæozoic Times."]

Another primitive and generalized genus mentioned in the text is _Archæocyathus_ of Billings, whose headquarters seem to be in the Lower Cambrian, and which may probably be traced farther back.

Mr. Billings described the genus in his "Report on Canadian Fossils" (1861-64), taking _A. profundus_, from the Lower Cambrian of L'Anse à 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 Geological Survey, collected by the late Mr. Richardson, at L'Anse à Loup, in Labrador, in what were then called Lower Potsdam rocks. Slices of the specimens 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. 35). Yet they could scarcely be referred to the group of porous corals known in much later formations 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 Foraminifera, and if so, they were very large and complex forms of that group, consisting of perforated 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 calcareous, and were of the species named _A. profundus_ by Mr. Billings. He had, however, referred to the same genus silicified specimens from a later formation, 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 Cambrian 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 from Spain. He states the results of his examinations very fully in a paper in the Journal of the _Geological Society of London_.[58] He retains the original name for the older and calcareous form from L'Anse à 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, _Archæoscyphia_. In this Walcott substantially agrees with Hinde in his "Memoir on the Lower Cambrian Fauna." Both seem to refer Archæocyathus to corals, though admitting its very exceptional and anomalous structure. I think, however, 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 Palæozoic with the Eozoic faunas. In my description of it in "The Dawn of Life" in 1875, I used the following terms:--"To understand Archæocyathus, 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 connected 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."

[Footnote 58: Vol. xlv., 1889, pp. 125 _et seq._]

On the whole, when we consider the magnitude and synthetic character of such forms as Cryptozoon, Receptaculites, and Archæocyathus, and their association with generalized types of Crustaceans and Brachiopods, we can scarcely fail to perceive that at the base of the Palæozoic we are leaving the reign of the higher marine invertebrates, and entering on a domain where lower and probably Protozoan 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 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 requirements of the Darwinian evolution. He then discusses 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 evidence, and dwells on the number of distinct types represented as far back as the Lower Cambrian. Independently of the interpretations and explanations 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 multiplied 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 enthusiast, who feels himself aggrieved if not supplied 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 explain 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 reasonable 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.

* * * * *

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 Möbius in his elaborated memoir in "Palæontographica" 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 meaning. 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. Möbius, 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 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,[59] and more especially to his retaining unchanged the description of _Eozoon Canadense_, 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.

[Footnote 59: _Nature_, March 17, 1892.]

Dr. Carpenter devoted much time to the study of Eozoon, and brought to bear on it his great experience of foraminiferal forms, and his wonderful 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 processes of slicing and etching, and by dexterous management of light, he could bring out the structure 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 discussing 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 specimens in our cabinet here, have since that time been noticed in my _résumé_ 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 their own negative conclusions in a matter of so much difficulty, and requiring so much knowledge of organic structures in various states of mineralization. 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 unexpected 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 structures in crystalline limestones when actually present. Since that publication also, the discoveries of Mr. Matthew in the Laurentian of New Brunswick, and 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 excellent 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 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 Laurentian or Huronian"; and I may add, that while it is certain that the beds containing them are pre-Palæozoic, 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 represented 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 Survey for 1894-95, containing the elaborate Memoir of C. R. Van Hise on the pre-Cambrian Geology of North America. It is a very valuable contribution to the literature of this difficult subject, and will constitute a standard book of reference: though I think the use of the term "Algonkian" for groups of beds which are in part basal Palæozoic and in part Eozoic or Archæan is to be deprecated, and scarcely sufficient 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. Tweeddale Atkin, of Egerton Park, Rock Ferry, in examining 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 cylindrical worm-burrows, and in the micaceous shales there are long cylindrical cords, which may be algæ of the genus _Palæochorda_, and also bifurcating fronds resembling _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 beds of limestone and dolomite associated with pre-Cambrian rocks, which Dr. Callaway regards as probably 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 preserved specimen of Cryptozoon, or some allied organism. 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 Palæozoic, 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-Palæozoic. Such rare intervals 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

PAGE

Adams on composition of Laurentian schists 108
---- his work on Laurentian stratigraphy 296
Animals, Cambrian, classes of 7, 11
---- pre-Cambrian 53
---- Huronian 67
---- Grenvillian 73, 303
Antiquity, relative 6
Aquatic animals, permanence of 13
Aragonite in fossils 117
Archæocyathus 35, 315
Archæozoon 214, 309

Barlow, his explorations 296
Bavaria, Eozoon of 71
Beecher on limbs of Trilobites 25
Bicknell on Eozoon 141
Billings on Eozoon 137
---- on Receptaculites 315
---- on Archæocyathus 316
---- on Signal Hill fossils 54
Bonney on Côte St. Pierre 142
Burbank on Chelmsford Eozoon 141

Calcarina 186
Calumet, Grand, Eozoon of 130
Canals of Eozoon 133
Cambrian, life of Early 17
---- geography of the 18
Carbon in Laurentian limestone 93
Carpenter, Dr., on Eozoon 137, 303, 324
Cayeux on Huronian fossils 68
Chambers, Mr. E. T. 313
Chrysotile, veins of 161, 239
Cœnostroma 174
Colorado cañon 56
Controversies respecting Eozoon 324
Corals, history of 32
Côte St. Pierre 88, 91
Cryptozoon 36, 56, 310

Dallinger, note on Eozoon 325
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 111
---- its laminæ and chambers 152, 157
---- its canals and tubuli 133, 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 specimens 68
---- fragments of, in limestones 183
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 111

Glauconite, mineralizing fossils 217, 298
Granular structure in Eozoon 165
Graphite of the Laurentian 93
Gregory on Eozoon 235, 325
Grenvillian series 39
Gresley on Huronian worms 68
Gümbel on European Eozoon 71, 213

Hall, Dr. James, on Cryptozoon 36, 310
Hanford Brook, section at 51
Hastings series (Huronian ?) 67
Hinde on Archæocyathus 34, 317
Hunt, Dr. Sterry, on indications of life 97
---- on silicates in fossils 298
Huronian system 65
Hymenocaris 27

Jones, T. Rupert, on Eozoon 75, 137
Jullien on Eozoon 235

Kewenian or Kewenawan series 48
King, Prof, on Eozoon 221
Laurentian system 71
---- its limestones 92
Lavis, Dr. Johnson, on Eozoon 235, 325
Life in Early Cambrian 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 Archæozoon 214, 309
---- on Etcheminian 48, 51, 54
McMullen as explorer 128
Möbius 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-Cambrian life 47
Pre-Cambrian rocks in Canada 76
Pre-geological evolution 320
Pre-Palæozoic life 216
Pyroxene in Eozoon 167, 169

Receptaculites 315
Robb, Pole Hill specimens 301

Serpentine, mineralizing fossils 147
---- different origins of 167, 171
Signal Hill series 53
Silicates, mineralizing fossils 217, 298
Spines, use of 30
Stromatoporæ 173
St. Pierre, Côte 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 Cañon 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

* * * * *

Transcriber Note

In order to accommodate placement of illustrations and footnotes, many paragraphs were split where it seemed reasonable. Minor typos were corrected. A web search shows that the anchorless Footnote on page 139 appears to reference the quoted text on page 140. Therefore, the Footnote was placed after the quoted text.

On page 174, Footnote 36 referred twice to Figure 8 and to a "Microscopic slice" as Figure 61 (which does not exist). It is assumed the intent was to refer to Figures 7, 7a, 8 and 59 and has been altered to point to those figures. The caption for Fig. 7 also refers to "Fig. 61, p. 310" and has been updated to "Fig. 59, p. 237".