VERTEBRATE ZOOLOGY. 485 



1. Antillean. 



2. Central American. 



3. Brazilian. 



IV. Indo-African realm, with 2 regions viz.: 



1. African region, with 3 provinces viz.: 



a. Eastern. 



b. Western. 



c. Southern. 



2. Indian region, with 2 provinces viz.: 



a. Continental. 



b. Insular. 



Y. South American Temperate realm, with 2 provinces 



viz.: 



a. Andean. 



b. Pampean. 



YI. Australian realm, with 3 regions viz.: 



1. Australian, with 2 provinces viz.: 



a. Australian. 



b. Papuan. 



2. Polynesian. 



3. New Zealand. 



VII. Lemurian realm, undivided. 

 VIII. Antarctic or South Circumpolar, undivided. 



It would be unadvisable to let this appear without some 

 cautionary remarks. 



Unquestionably temperature exerts a very great influence 

 over the distribution of life; and a naturalist who first ap- 

 proached the subject of zoological geography from a consid- 

 eration of marine animals might very well have an exagger- 

 ated idea of its importance. There is, or has been, within 

 recent o-eolorrical times, such a free circulation of the sea that 

 no great obstacles intervened to the diifusion of many forms, 

 wherever the conditions were favorable. Temperature, in- 

 deed, was one of those conditions, and the distribution of 

 marine animals is essentially coincident with thermometric 

 zones. But a divergence of continental areas has prevailed 

 from a distant geological epoch, and, as a matter of fact, the 

 animal associations of the several great isolated continental 

 areas are, on the whole, very distinct, and their differentia- 

 tion, it may be assumed, has advanced pari passu with that of 



