420 Notices of Books . (July* 
and the Oriental regions of Mr. Wallace, thrown together, form 
the Indo-African realm of Mr. Allen ; or rather, we may say, 
that he takes the two primary divisions of Mr. Wallace, and 
reduces them to a secondary rank. Madagascar and the Masca- 
renes, instead of viewing as a zoological province of Africa, he 
elevates to the rank of a primary realm — a view with which we 
feel disposed to agree. Concerning the Australian region the 
two authorities agree almost entirely as far as boundaries are 
concerned, though Mr. Allen decidedly refers to his Indo-African 
realm the Philippine group, which Mr. Wallace leaves doubtful, 
and also Celebes. As regards the subdivisions of the Australian 
realm, Mr. Allen includes in his Papuan province not merely New 
Guinea, with the smaller islands to the west and the south-east, 
but Australia proper north of 20° S. lat., which he considers here 
as approximately representing the isotherm of 70° F. 
Into the evidence which the author adduces in support of his 
classification, and the objections which may be urged against it, 
space does not at present allow us to enter. He appears to have 
abandoned his formerly proposed separation of Temperate South 
Africa as a primary realm because it lies “ wholly within the 
warm-temperate belt, and widens rapidly northward to abut very 
broadly against the torrid zone.” Yet this latter feature belongs 
no less decidedly to Temperate South America, for which the 
author still claims the rank of a primary realm. A corollary 
which can scarcely have escaped the reader is formally stated 
towards the close of this most interesting treatise : — “ The 
northern circumpolar lands may be looked upon as the base or 
centre from which have spread all the more recently developed 
forms of mammalian life, as it is still the bond which unites the 
whole. Of the few cosmopolitan types that in a manner bind 
together and conned! the whole mammalian fauna of the globe 
(the I.emurian and Australian Realms in part excepted) nearly 
all have either their true home or belong to groups that are 
mainly developed in the northern lands. But if this be true of 
the mammalia must it not hold good of all the great animal 
groups, and indeed of plants also ? If not, the value of the 
mammalia as a guide to the determination of zoological regions 
becomes exceedingly doubtful. But if so, we are led to the 
conclusion that the dawn of life must have been not in the 
equatorial, but the ardlic regions, and that not merely the first 
animal forms altogether, but the first of each, at least of the 
grand divisions of the animal kingdom, must have been there 
developed. 
It is obviousiy impossible in a brief notice like the present to 
do justice to a work which will doubtless receive from biologists 
wide-spread and serious attention. If Mr. Allen’s time and 
duties permit it, he could scarcely confer a more valuable boon 
upon science than the working out of his hypothesis for the 
animal world at large. 
