Charles Lyell has brought forward several arguments, especially, (1) that "several of the great lakes are by no means in the position which they ought to have taken had they been scooped out by the pressure and onward motion of the extinct glaciers;" (2) that lakes of the first magnitude do not occur "in several areas where they ought to exist if the enormous glaciers which once occupied those spaces had possessed the deep excavating power ascribed to them; (3) that the presence of patches of preglacial freshwater formations in some Alpine valleys, e. g. on the borders of the Lake of Zurich, prove that some of the lakes must have existed before the glacial period.

Sir Charles Lyell seems, however, in this instance, more fortunate in opposition than in proposition. He has shown that the "erosive power of ice was not required to produce lake-basins on a large scale," by means of the preglacial lacustrine formations of the Lake of Zurich. Some other cause must then have produced them if glaciers did not excavate them, and Sir Charles Lyell suggests "unequal movements of upheaval and subsidence." This theory ought to be capable of proof or refutation by geological surveyors, and no doubt it will sooner or later be submitted to the test; but until that is done little more can be said about it, than that it does not enlist in its favour the sympathies of those who have been trained by Sir Charles Lyell himself to the application of the doctrine of Uniformity.

The Antiquity of Man' was published as a résumé of the evidence which has recently been accumulated in favour of the contemporaneity of Man with certain extinct Mammalia. It was avowedly a compilation; but it contains a large mass of matter drawn from a variety of sources, and tending to strengthen the evidence in favour of Man having existed on the earth in Postpliocene times. Perhaps not even the Principles' exhibits more clearly the author's wonderful faculty of "assimilation," as Dr. Fitton called it, of turning anything and everything into good geology. But it is unnecessary for us to discuss this subject at greater length, except incidentally, as being one of the last discoveries bearing on a view of the succession of life in time which Sir Charles Lyell has persistently maintained ever since the commencement of his distinguished career.

Negative evidence has always been a battle-ground for geologists holding opposite views, and it is only of late years that its use has fallen considerably in estimation. The experience of the last halfcentury has taught geologists that it is highly unphilosophical, and positively unsafe, to assume that any class of organisms has not existed at any particular period, or that there is a total break in the succession of life on the earth at any horizon in the geological scale, merely because we have no positive evidence in proof of the

contrary. But Sir Charles Lyell can claim the merit of having foreseen the unstable nature of conclusions based on ignorance, for in the first edition of the 'Principles' he contended that the apparent breaks in the continuity of geological periods are due to our imperfect information, and do not really exist in nature; and also that the organic remains imbedded in known deposits do not represent the whole of the earth's inhabitants during those periods or in those regions; and he devoted some considerable space to the illustration of these views, in contrast with the then prevalent doctrine of catastrophes.*

In those days Lamarck's hypothesis of progressive development by transmutation of species excited a great deal of discussion; as also did the theory of the successive appearance on the earth's surface of more and more highly organized animals and plants. In support of the latter view, geologists appealed with alacrity to the fossils discovered in different deposits as affording a positive proof of its truth; and they thus endeavoured to define the order of nature, and to assign to each class of organisms the period of its birth. But Sir Charles Lyell contended † that at that time there was "no foundation in geological facts, for the popular theory of the successive development of the animal and vegetable world, from the simplest to the most perfect forms." And although subsequent discoveries have abundantly justified Sir Charles Lyell's protest against invoking negative evidence, to prove that this or that period witnessed the creation of such or such a class of organisms, he has at last admitted that the successive development theory is not much affected by successive discoveries, and is probably necessary in the present state of science. It appears to us, however, not a little mischievous, in so far as it encourages an appeal to negative evidence, as was amusingly illustrated in 1851 by the late Professor Edward Forbes, in reference to the discovery of Pulmonifera in the Purbeck beds, "the (supposed) non-existence of which during the Secondary epoch has called forth not a few prematurely wise comments in geological works."

Agassiz just had given his bail,

"Twas adverse to creation,

That there should live pulmoniferous snail,
Before the chalk formation."§

Since then Pulmonifera have been discovered in Carboniferous deposits, and the history of nearly every group of animals contains a record of similar premature conclusions and their subsequent refutation.

* See also his Presidental Address to the Geological Society in 1851, passim.

+ Principles,' 1st edit., vol i., p. 153.

Antiquity of Man,' p. 405.

Wilson and Geikie's ‘Memoir of Edward Forbes,' p. 461.

Now to what conclusion does the sum of the evidence at present in our possession point? It cannot be denied that, as regards animals, the Protozoa are those of which we have the earliest evidence, in the Eozoon Canadense of the Laurentian rocks, if that primæval fossil be of organic origin. Whether the Coelenterata, Echinodermata, Mollusca, or Crustacea first appeared we have no evidence to show, as it is extremely improbable that the Eozoon was the solitary inhabitant of the seas during the Laurentian period. Known facts are in favour of the Annulosa appearing before either of the other great groups; whereas, according to the successive development, theory, they ought to have appeared in the order in which they have been mentioned. But this evidence is purely negative, and therefore of little or no value. As regards the Vertebrata it is certain that we are cognizant of Fishes older than any Amphibia, and these again are older than any known Reptiles. The oldest true Reptile is probably Triassic, and thus older than either Birds or Mammals; but with regard to the order of appearance of these two classes, we meet with the same difficulty as before. Now the Vertebrata as a whole form a group of equal value with the Mollusca, Annulosa, &c., and should consequently be compared as a whole with the latter, not, as is usual, in four or five separate groups. From this point of view we should find that the present state of our knowledge lends very little countenance to the theory of uniform progression of animal life in time; and if we base our comparison on groups of smaller value the general result is much the same; for, as was shown by Professor Huxley, "if the known geological record is to be regarded as even any considerable fragment of the whole, it is inconceivable that any theory of a necessarily progressive development can stand, for the numerous families and orders cited afford no trace of such a process." Nevertheless Sir Charles Lyell remarks, "It would be an easy task to multiply objections to the theory now under consideration; but from this I refrain, as I regard it not only as a useful, but rather, in the present state of science, as an indispensable hypothesis, and one which, though destined hereafter to undergo many and great modifications, will never be overthrown."t

This conviction was probably produced by the necessity which Sir Charles Lyell felt of abandoning his old opposition to the theory of the transmutation of species after carefully weighing Mr. Darwin's theory of Natural Selection. Sir Charles Lyell appears to think that there is a necessary and direct connection between these theories; but, on our part, we cannot see why a naturalist may not be an advocate for "descent with modification," and still refuse to accept the theory of progressive development. It is therefore rather surprising to read in the concluding sentences of Chapter XX. of the † Antiquity of Man,' p. 405.

* Ann. Address Geol. Soc.,' 1862.

Antiquity of Man,' an attempt to account for the apparent paradox, "that writers who are most in favour of transmutation are nevertheless among those who are most cautious, and one would say timid, in their mode of espousing the doctrine of progression; while, on the other hand, the most zealous advocates of progression are oftener than not very vehement opponents of transmutation." Sir Charles endeavours to explain it by the belief of the former in the incompleteness of the geological record, and of the latter in its completeness; but it appears to us that there is a great deal more in the caution of the Darwinian than is dreamt of even in Sir Charles Lyell's philosophy.

So long as the doctrine of " transmutation of species" possessed only the old and crude form given to it by Lamarck, and so clearly illustrated by the author of the Vestiges,' Sir Charles Lyell attacked it with considerable vehemence. But a careful consideration of the theory of Natural Selection, and frequent conversations with Mr. Darwin on the subject, have had the effect we should have anticipated on the opinions of so thorough a master of the mode in which the causes of change operate. The principle involved in Mr. Darwin's hypothesis is one congenial to the mind of the author of the 'Principles.' A cause producing a small effect, which becomes greater and greater in the course of ages by successive repetitions, is one of all others most calculated to enlist the sympathies and charm the mind of the man who has for thirty-six years been endeavouring to establish the self-same idea in its application to inorganic nature. So we were not surprised to find Sir Charles Lyell, in the Antiquity of Man,' bringing to bear the vast and varied mass of information at his command in favour of the probability of the new doctrine. We were disappointed at not finding more light thrown on it from a geological point of view; but this defect will no doubt be remedied in the forthcoming edition of the 'Principles,' and is to a great extent compensated by some beautifully conceived arguments drawn from the analogy supplied by other fields of inquiry.

It is not now our intention to discuss the theory of descent with modification, that has very recently been done in this Journal;* but we shall examine two or three of Sir Charles Lyell's arguments in its favour, not so much on account of their illustrating the theory itself, as because they throw light on the nature of the predominating feature in the mental constitution of Sir Charles Lyell himself,--an object which we have had in view throughout this review of his labours.

Perhaps the most remarkable of these arguments is that drawn from the very clever comparison of a natural history species to a language, and consequently of Mr. Darwin's theory to the Aryan

* No. 10, April, 1866, pp. 151–176.

hypothesis. Considering that the Antiquity of Man' was written for the educated public, not specially for naturalists, it scarcely seems possible to conceive of a comparison better calculated to bring home to the understanding a proper appreciation of the aim and scope of the theory of "descent with modification." Professor Max Müller has observed, "That if we knew nothing of the existence of Latin, if all historical documents previous to the fifteenth century had been lost, if tradition even was silent as to the former existence of a Roman empire, a mere comparison of the Italian, Spanish, Portuguese, French, Wallachian, and Rhotian dialects would enable us to say that at some time there must have been a language from which these six modern dialects derive their origin in common." Further, "Latin itself, as well as Greek, Sanskrit, Zend (or Bactrian), Lithuanian, old Sclavonic, Gothic, and Armenian are also eight varieties of one common and more ancient type, and have all such an amount of mutual resemblance, as to point to a more ancient language, the Aryan, which was to them what Latin was to the six Romance languages. Now if we substitute for the names of these various languages the designations of allied species of animals or plants, having similar chronological relations, and if for the words "dialect" and "language" we substitute "species" and "variety," and so on, we have in these sentences a correct exposition of the doctrine of transmutation as applied to certain particular cases. The analogy is complete.

But this is not all: Sir Charles Lyell shows that the objections which would naturally be made by an illiterate person to the Aryan hypothesis are precisely parallel to those often made to Mr. Darwin's theory; e. g. "We all speak as our parents and grandparents spoke before us," &c. Then there is the same difficulty about the definitions of terms as in Natural History; for instance, "If this theory of indefinite modifiability be sound, what meaning can be attached to the term language, and what definition can be given of it so as to distinguish a language from a dialect?" We need not follow the comparison further; sufficient has been quoted to show the parallelism of the two cases, and the skill with which Sir Charles Lyell has brought into relief those points of the Aryan hypothesis which bear the most striking similarity to the theory of Mr. Darwin.

In conclusion, we must refer to Sir Charles Lyell's treatment of the charge of Darwinism being inconsistent with the existence of a Creator and the immortality of the soul. A reviewer asks, if there was a transition from the instinct of the brute to the noble mind of man, "at what point of his progressive improvement did Man acquire the spiritual part of his body, and become endowed with the awful attribute of immortality?" Sir Charles Lyell appeals *Antiquity of Man,' pp. 454, 455. † Antiquity of Man,' p. 502. VOL. IV.