Eozoon Research Articles

Eozoön Canadense "The Dawn Animal of Canada"

17OZOON CANADENSE, dawn animal of Canada, was found in the PreLcambrian rocks of eastern Canada in 1858. The discovery startled the geological world, since at the time few paleontologists believed that such metamorphic rocks could preserve fossils or even that life could have existed so long ago. In fact, what we now call Precambrian was then commonly designated by the term Azoic-lifeless. It is not surprising, then, that the authenticity of Eozoon canadense was disputed. The ensuing controversy lasted for nearly fifty years and developed into of the most contentious issues in nineteenth-century geology. While the inorganic nature of Eozoon has long been established and Eozoon is no longer of scientific interest, the controversy has significance for the history of science. It provides an example of the manner in which every aspect of nineteenth-century paleontology was scrutinized for its bearing on evolution. It is also a classic case of the confrontation of younger specialists with each other and with the older generation of broadly trained naturalists. There were two chief reasons for the persistence of the dispute. Most obvious and most important was the inability of early paleontology to settle the matter. The second reason, seldom stated by the disputants, was the significance of Eozodn in the larger issue of derivation of species. For, were Eozoon proved to be organic, evolutionists would be confronted with the most impressive of all gaps in the paleontological record, a gap that would give pause to even the most ardent evolutionist. the other hand, if this gap were successfully explained or overcome by the finding of subsequent forms related to Eozoon, the evolutionists could rejoice in having found, at the earliest date of known animal life, the simplest of life, a reasonably akin to the one primordial form of Darwin's speculation.' In short, there was something at stake for both sides in the greater scientific controversy. Darwin himself was interested in Eozoon and its promise for his position. He introduced Eozoon into the fourth edition of The Origin of Species: After reading Dr. Carpenter's description of this remarkable fossil, it is impossible to feel any doubt regarding its organic nature.'2 Darwin cited Eozoon in his famous tenth chapter, On

LVII.—On the structure of Stromatoporoids and of Eozoon

LVII.—<i>On the structure of Stromatoporoids and of</i> Eozoon

Geology at the British Association

THE President of this Section devoted his address mainly to stratigraphical geology, and we may well follow his example, and consider the papers presented to the Section in a similar order. Beginning with the oldest rocks, the first paper to claim attention is that by Sir W. Dawson, on pre-Cambrian Fossils. A valuable portion of this paper summarised our knowledge of the succession of Canadian rocks of high antiquity. He regards Matthew's Protolenus zone of New Brunswick as the equivalent of the Olenellus zone, and beneath this occurs a mass of greenish slates and conglomerates with a few doubtful fossils, such as brachiopods, ostracods, and protozoans. These Etcheminian rocks rest on the Huronian rocks, which contain worm-burrows, sponge spicules, and laminated forms comparable to Cryptozoon and Eozoon. Under these comes the Grenvillian system, or Upper Laurentian rocks, with Eozoon in the limestones, and at the base the orthoclase gneiss and hornblendic schists, which constitute the Lower Laurentian. The author exhibited a series of lantern slides showing the structure and composition of Eozoon canadense, amongst them being many very beautiful decalcified specimens, which none of those who criticised the paper attempted to explain.

Pyroxene and Serpentine in Association with Eozoön Canadense

Pyroxene and Serpentine in Association with Eozoön Canadense

II.—On the Mode of Occurence of Eozoon Canadense at Côte St. Pierre

The question of the origin of Eozoon Canadense has been recently revived in an important and most interesting paper on a similar structure in blocks of limestone ejected from Vesuvius. The writers, however, of that paper evidently found that more information existed as to the microscopic structure of the Canadian Eozoon than as to its mode of occurrence, so that a few notes on this subject may be of some use as a contribution to the discussion. I visited one of the most noted localities for Eozoon—Côte St. Pierre—in 1884, when I had the inestimable advantage of being conducted by Sir J. W. Dawson, to whose unwearied kindness and hospitality I was so often indebted during my stay in Canada. I made careful notes and rough sketches of what I saw, collected a fair suite of specimens, and paid especial attention to the relation of the structure to other parts of the rock-masses. Upon the question of the origin of Eozoon I do not purpose to enter: I shall restrict myself to stating facts of which, as it seems to me, account must be taken in all attempts to interpret this extraordinary structure.

Carpenter on Eozoon

THE scientific world is deeply indebted to Dr. Dallinger for liis excellent new edition of Carpenter's invaluable work on the microscope, and among other things for his retaining unchanged the description of Eozoon canadense, as a monument of an important research up to a certain date.

The Tudor Specimen of Eozoon

The unanimity with which the view of the organic origin of Eozoon canadense was received on its announcement in 1865 by Sir William Logan, Dr.(afterwards Sir J. W.) Dawson, and Dr. W. JB. Carpenter, in the Quarterly Journal of this Society, was first seriously broken by the publication, in the succeeding volume, of the memoir by Professors King and Kowney “On the so-called Eozoonal Rock”. In the following year the Quarterly Journal contained a series of “Notes on Fossils recently obtained from the Laurentian Rocks of Canada, and on objections to the organic nature of Eozoon ” by Dr. (afterwards Sir J. W.) Dawson, the most valuable contribution in which was the description of a specimen found by Mr. H. G. Vennor in a limestone belonging to the Hastings series at Tudor, Hastings county, Ontario. This was identified as Eozoon canadense , though as possibly a new variety, by Sir J. W. Dawson, who seemed to consider that this discovery relieved him of the necessity of making any detailed reply to the arguments of his critics, as “furnishing a conclusive answer to all those objections to the organic nature of Eozoon which have been founded on comparisons of its structures with the forms of fibrous, dendritic, or concretionary minerals—objections which, however plausible in the case of highly crystalline rocks, in which organic remains may be simulated by merely mineral appearances readily confounded with them, are wholly inapplicable to the present specimen ” §. The importance of the new discovery depended on the

On the ophiolite of Thurman, Warren Co., N.Y., with remarks on the eozoon canadense

On the ophiolite of Thurman, Warren Co., N.Y., with remarks on the eozoon canadense

Scientific Serials

American Journal of Science, March.—Some determinations of the energy of the light from incandescent lamps, by Ernest Merritt. Two series of experiments are described, which have been carried out for the purpose of determining what portion of the energy supplied to a lamp is given off as light, and what proportion is wasted practically as dark heat. In the first, based on Melloni's calorimetric method, the light is separated from the dark heat by passing the radiations to be measured through a thin layer of water, or, better still, through a solution of alum in water. The energy of the dark heat, which is almost entirely absorbed, is then measured by the rise in temperature of the water, and that of the light by a thermopile. In the second process the calorimeter was abandoned, and a cell, I decimetre thick, containing a strong solution of alum, was used for absorbing the dark heat. The light, after passing through this cell, was allowed to fall on a thermopile, and the deflection was observed. Then the alum cell was removed, and the deflection corresponding to total radiation was observed, the ratio of the two deflections giving the ratio of the light energy to the total energy. This being determined by electrical measurements, the energy of the light could be calculated.—On the ophiolite of Thurman, Warren County, New York, with remarks on the Eozoon canadense, by George P. Merrill. This ophiolite, a kind of verdantique marble, is found to be an alteration, or meta-somatic product after a mineral of the pyroxene group. Its constitution promises to throw some light on the Eozoon problem.—On the origin of the deep troughs of the oceanic depression; are any of volcanic origin?, by James D. Dana. A general survey of the oceanic regions leads to the inference that volcanic action can only have had a very subordinate part in determining the origin and position of the great marine depressions. Their source must be sought still less in superficial causes, such as erosion, but rather in the interior agencies of primordial development. The paper is accompanied by a bathymetric map of the Pacific and Atlantic, based on the recent charts of the British and United States Hydrographic Departments.—Description of a problematical organism from the Devonian, at the Falls of the Ohio, by F. H. Knowlton. These puzzling organisms, here provisionally named Calcisphæra lemoni, from the collector, have been submitted to various American and European palaeontologists, and the evidence both for and against the view that they are a fruit of Chara, is given in detail.—Papers are contributed by George H. Williams, on the geology of the Island of Fernando de Noronha (part 2, petrography); by S. L. Penfield, on some curiously developed pyrite crystals from French Creek, Delaware County, Pennsylvania, and on some crystallized bertrandites from Maine and Colorado; and by J. S. Diller and J. E. Whitfield, on dumortierite from New York and Arizona, peridotite from Kentucky, and gehlenite occurring in furnace slag in Pennsylvania.

On the ophiolite of Thurman, Warren County, New York, with remarks on the Eozoon canadense.

On the ophiolite of Thurman, Warren County, New York, with remarks on the Eozoon canadense.

On New Facts relating to Eozoon Canadense

On New Facts relating to Eozoon Canadense

On New Facts relating to Eozoon Canadense

On New Facts relating to Eozoon Canadense

On New Facts relating to Eozoon Canadense

On New Facts relating to Eozoon Canadense

An Old Chapter in the Geological Record with a New Interpretation; or Rock Metamorphism (Especially of the Methylosed Kind) and its Resultant Imitation of Organisms. With an Introduction Giving an Annotated History of the Controversy on the so-called “Eozoon Canadense,” and an Appendix. By ProfessorsKing and Rowney. pp. 183 (including introduction), with cuts, and 9 coloured plates. (Van Voorst, 1881.)

An Old Chapter in the Geological Record with a New Interpretation; or Rock Metamorphism (Especially of the Methylosed Kind) and its Resultant Imitation of Organisms. With an Introduction Giving an Annotated History of the Controversy on the so-called “Eozoon Canadense,” and an Appendix. By ProfessorsKing and Rowney. pp. 183 (including introduction), with cuts, and 9 coloured plates. (Van Voorst, 1881.)

Principal J. W. Dawson's criticism of my memoir on the structure of Eozoon canadense compared with that of Foraminifera

Principal J. W. Dawson's criticism of my memoir on the structure of Eozoon canadense compared with that of Foraminifera

Scientific Serials

American Journal of Science and Arts, March.—In the opening paper Prof. Norton contends that under varying conditions the ultimate molecules of bodies are subject to changes in the intensity of their attraction or repulsion, at a given distance of neighbouring molecules (temperature and chemical constitution remaining constant). Evidence of this is found in the phenomena of permanent distortion of materials after temporary subjection to a force of stress; in observed changes in the mechanical properties of materials, through tension, pressure, heat, &c.; change of mechanical properties of a body through presence of minute quantities of other substances; and certain facts in chemical physics (phenomena of solution, allotropy, the nascent state, &c.). The hypothesis is advanced, that the ethereal atmosphere condensed round an atom by its attractive action consists of an atmosphere of luminiferpus ether, and an envelope of electric ether immersed within this for a certain depth, an ethereo-electric atmosphere, in fact.—Some observations on flocculation of small particles (or their tendency to form, under moderate agitation, granular aggregates or compound particles of larger size), are described by Prof. Hilgard, and have important physical and technical bearings, especially on points in agriculture.—Prof. Dawson points out what he considers defects and errors in the method of investigation pursued by Prof. Möbius recently with regard to Eozoon canadense, leading to a decision adverse to the organic character of that object.—Mr. White offers some remarks on the Jura-trias of Western North America; Mr. Fontaine continues his notes on the mesozoic strata of Virginia, and Mr. Bannister contends for the hypothesis of the transition character of the Rocky Mountain lignite series, or Laramie group.—Some new species of anthozoa and cephalopoda added to the marine fauna of the eastern coast of North America, are described by Prof. Verrill; the cephalopoda have some specially interesting features.—Mr. Penfield gives analyses of triphylite.

Want of a systematic universal nomenclature in mineralogy

I suppose that many, only on account of its curious title, will take no notice of the following paper, because the words, Nomenclature in Mineralogy, do not denote something real or abstract at all. Nevertheless, I venture to hope that, sooner or later, a systematical nomenclature will make its appearance, since it is a real want in the further progress of this science. Botany and zoology,—and also that part of geology, which is called palaeontology,—have, as it were, an international language. In English, or Russian, or German, or French, zoologists know at once what is meant by names such as Hyaena striata, Bos caffer, Passer capensis, c and the botanists of these and other countries cannot be in doubt about the meaning of the Latin words, Primula veris, Lamia alba, Gentiana alpina, &c., or the palaeontologist about such names as Ursus spelaeus, Terebratula elongata, Eozoon canadense. But how can a Hungarian mineralogist understand what an English mineralogist means by bog iron ore, or a French mineralogist by feroxyde massif argilifere? He cannot ascertain the true meaning of such words as orpiment, arsenic sulfure jaune, melaconite, chessylite, muriate of mercury, &c., and even should there exist a similarity between these and the corresponding Hungarian words, he can never be quite certain of understanding them correctly. The English and other mineralogists meet with the same inconvenience whenever they go to countries where their respective languages are not spoken. The same difficulty presents itself within the languages themselves. Take, for instance, the English,

III.—Eozoon canadense, according to Hahn

III.—Eozoon canadense, <i>according to Hahn</i>

XXIV.—Is there such a thing as Eozoon canadense? A microgeological investigation

XXIV.—<i>Is there such a thing as</i> Eozoon canadense? <i>A microgeological investigation</i>

XIV.—On Mr. Carter's objections to Eozoon

XIV.—<i>On Mr. Carter's objections to</i> Eozoon