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Notices of Books. 
at the present day dependent upon conditions of climate alone. 
He does not, however, at all question the conclusion, supported 
as it is by a vast accumulation of evidence, that the climate of 
Central Europe in the Eocene period was tropical, whilst that 
of the Miocene approximated in temperature to Florida or 
Louisiana. 
The view, once prevalent, that fossils are not the remains or 
casts of animals once living, but lasus nature? formed by some 
“ plastic virtue latent in the earth,” or, worse still, as Mr. Gosse 
most irreverently, in our opinion, insinuates, forged documents 
to mislead mankind, Dr. Nicholson pronounces contrary to the 
common sense of scientific men. 
The chapter on the “ Biological Relations of Fossils,” and 
still more that on the “ Succession of Life upon the Globe,” 
bring the author face to face with the great biological question 
of the day, the origin of species. His views on this subject 
attradl the more interest as he has been to some extent misun- 
derstood, if not misrepresented. Certain of the remaining advo- 
cates of the old school of Natural History have invoked him as 
a kind of successor to Agassiz and an ally of that redoubted 
dispenser of teleology and magniloquence, Principal J, W. 
Dawson. But we see no ground on which they can claim Dr. 
Nicholson as belonging to their fraternity. He decidedly recog- 
nises organic evolution. “ The palaeontologist,” he writes, “ is 
so closely confronted with the phenomenon of closely-allied forms 
of animal life succeeding one another in point of time, that he 
is compelled to believe that such forms have been developed from 
some common ancestral type by some process of evolution.” 
If he adds that there “ has also been at work some other deeper 
and higher law on the nature of which it would be at present 
futile to speculate,” he says little more than what every cautious 
thinker must admit. Natural selection, sexual selection, changing 
climatic influences, disuse of organs, explain much. Do they 
explain all ? That Dr. Nicholson can rank among the opponents 
or enemies of Darwin — for there are those who deserve the latter 
rather than the former appellation— no one who reads the final 
sentence of this book can admit. “ In the successful solution of 
this problem will lie the greatest triumph that palaeontology can 
hope to attain ; and there is reason to think that, thanks to the 
guiding clue afforded by the genius of the author of the 1 Origin 
of Species,’ we are at least on the road to a sure, though it may 
be a far distant, vidtory.” 
The illustrations are numerous, carefully executed, and judi- 
ciously selected. To each period is appended a list of the prim * 
cipal works and memoirs which the student may require to 
consult for more detailed information. There is also an elaborate 
glossary of technical terms employed, an extensive index, and a 
“ tabular view of the chief divisions of the animal kingdom,” in 
which, however, we regret to perceive that the Mollusca are 
2 P 2 
