DR. pbichabd'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 maybe 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. t 

 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. f Pre'- ^is. N. H. p. 214, 



