Notices of Books. 
403 
1878.] 
docftrine of the secular cooling of the earth ; it is contradicted 
by the fossils of the period, which show that the seas were 
colder than at present, and if it existed it could not produce the 
effects required, unless a preternatural arrest were at the same 
time laid on the winds which spread the temperature of the sea 
over the land.” 
The author has “ failed to find, even in our higher mountains, 
any distinCt signs of glacier aCtion, though the aCtion of the 
ocean-breakers is visible almost to their summits ; and though 
I have observed in Canada and Nova Scotia many old sea- 
beaches, gravel-ridges, and lake-margins, I have seen nothing 
that could fairly be regarded as the work of glaciers.” He holds 
that while a great and marked climatic revolution has occurred 
in Europe, the evidences of such a change are very much 
slighter in America, where the causes of the coldness of the 
post-pliocene seas to some extent still remain. The author, in 
the following passage, admits substantially the existence of a 
former epoch of intense cold : — “ In the Tertiary era there was 
much dry land in the northern hemisphere, and multitudes of 
large animals now extinCt inhabited it, apparently under a 
climate milder than at present. Great changes, however, took 
place in the relative positions of land and water, inducing very 
important changes of climate, which finally became of an almost 
arctic character over all the present temperate regions . The 
greater part of Northern Europe and Asia appear to have sub- 
sided beneath the waters of the boulder-bearing semi -arctic 
ocean.” It would almost seem that Dr. Dawson attributes the 
climatic deterioration to a decrease of land in the higher lati- 
tudes, taking thus a view opposite to that of Lyell. We fear 
that the very foundations for a thorough settlement of the gla- 
cial question stand in need of careful revision. 
In closing this interesting and instructive volume we can only 
pronounce it indispensable to every geologist. 
A Manual of Zoology for the Use of Students. By H. Alleyne 
Nicholson, M.D., D.Sc., &c. Fifth Edition, Revised and 
Enlarged. Edinburgh and London : W. Blackwood and 
Sons. 
When a scientific work has, like the volume before us, reached 
its fifth edition, and has met with the general approval of the 
highest authorities, the task of the critic is greatly simplified. 
There are indeed points on which issue might be joined, and 
there also topics on which somewhat fuller information might be 
desirable. Thus, we cannot pronounce the common British 
centipede harmless, having received from one a bite decidedly 
more severe than the sting of the wasp. The bite of the viper, 
2 D 2 
