I884.J 
Analyses of Books. 
299 
Where did Life Begin ? A brief Enquiry as to the Probable 
Place of Beginning, and the Natural Courses of Migration 
therefrom, of the Flora and Fauna of the Earth. A Mono- 
graph. By G. Hilton Scribner. New York: Charles 
Scribner’s Sons. 
The author’s hypothesis is substantially that at the very outset 
of geological time the earth’s surface first became sufficiently 
cooled and consolidated to admit of the existence of animal and 
vegetable life at or near the North Pole, and that with progressing 
refrigeration the fauna and the flora were gradually driven down 
towards the tropics, becoming more and more differentiated the 
farther they receded from the place of their origin. This view, if 
not explicitly stated, is shadowed forth in Mr. J. A. Allen’s 
system of animal geography, and is even, to a certain extent, 
implied in a remark by Mr. A. R. Wallace. The latter naturalist 
likens the existing continents to some huge tree, having its roots 
in the Ardtic regions, filling great part of the torrid and temperate 
zones with its matted boughs, and sending out three out-shoots 
towards the South Pole. This similitude certainly suggests that 
the flora and the land fauna would correspond in their origin and 
migrations to the growth of their home. 
The first question we have to ask is one which can only be 
solved by the physicists. Did the earth’s crust really become 
first solidified at the poles ? On this point we must confess our- 
selves unable to pronounce a valid opinion. 
Perhaps, however, even the contrary view, i. e., the simulta- 
neous solidification of the earth’s crust, would not be necessarily 
fatal to Mr. Scribner’s hypothesis. We can easily conceive that 
under those circumstances the poles would be the coolest parts of 
the earth, whilst the intermediate regions were still too hot for 
animal or plant. 
If the physical difficulties of the case can be got over, the evi- 
dence seems decidedly in favour of the author’s view. The 
fadts of animal geography seem in favour of migrations directed 
from north to south, rather than from east to west, or vice versa. 
Within the Ardtic circle the fauna shows comparatively little 
differentiation, so that Mr. J. A. Allen proposes in his classifica- 
tion one single Ardtic region. Within the temperate zones the 
Palseardtic and Neardtic regions of Dr. Sclater and Mr. Wallace 
have still so much in common that Mr. Allen feels authorised to 
consider them as one primary region. As we go farther south 
the divergence increases. The fauna of Africa and South Ame- 
rica are sharply contrasted. 
Again, if we look at the palaeontology of the case, we find 
evidence in high northern latitudes of a flora of temperate, or 
even subtropical, charadter, — proof of a climate very different 
from, and much superior to, that of lat. 55 0 to 6o° at the present 
day. 
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