DR. PRICHARD’S THEORY. 13 
attempted a more natural theory of animal distribution. 
This intelligent writer has looked more to the configu- 
ration of the earth, and to the natural connection or 
separation of its parts by intervening islands or oceans, 
than to absolute limits of longitude or latitude. Ac- 
cordingly, from this very circumstance, his zoological 
divisions are formed with much greater attention to 
nature than any of his predecessors. The following are 
the primary divisions he has proposed: —1. the arctic 
regions of the New and the Old World; 2. the tem- 
perate ; 3. the equatorial or tropical; 4. the Indian 
islands ; 5. the islands of New Guinea, New Britain, 
and New Ireland, and those more remote in the Pacific 
Ocean ; 6. Australia proper; and, lastly, the southern 
extremities of America and Africa.* 
(18.) The objections that may be stated against these 
divisions chiefly arise from the author not having kept 
in view the difference between affinity and analogy, as 
more particularly understood by modern naturalists. 
And we may illustrate this position by looking more 
attentively to the animals of two or three of these pro- 
vinces. 1. The arctic regions of America, Europe, 
and Asia, indisputably possess the same genera, and in 
very many instances the same species ; and if it should 
subsequently appear that these regions are sufficiently 
important in themselves to constitute a zoological pro- 
vince, then it is a perfectly natural one ; for not only 
are the same groups, but even the same species, in se- 
veral instances, common to both. But can this be said 
of the second of these provinces, made to include the 
temperate regions of three continents ? Certainly not. 
We find, indeed, analogies without end, between their 
respective groups of animals, but they have each a vast 
number of peculiar genera ; and so few are the species 
common to all three, that the proportion is not perhaps 
greater than as 1 to 50. The genera, with but very few 
* Dr. Prichard’s Researches, vol. i. p. 53. + Prel. Dis. N. H. p. 214. 
