PRESIDENT'S ADDRESS. 25 



will be remembered, there are fundamental differences involved in 

 this respect between the views of Messrs. Wallace and Allen. Mr. 

 Wallace's sequence of his " regions " implies a reminiscence of an 

 ancient idea, which was expressed in the translation of the terms 

 "Old World" and "New World" into respectively "Palseogsea" 

 and ' ' Neogaea ' ' The realms of Mr. Allen traverse such primary 

 groups, and are rather subordinated to climatic considerations. S till 

 other groupings have been proposed, as, for example, by Professor 

 Huxley, who has segregated the Eurasiatic, Indian, and African 

 realms into an "Arctaeoga," and the South American, or Austro- 

 Columbian, Australasian, and New Zealand ones into a " Notogaea. ' ' 

 And the present author has proposed to contrast the North Ameri 

 can, Eurasiatic, and Indian realms under the denomination Cen- 

 og<za, with an Eogaa, comprising the African, South American, 

 Australian, and New Zealand realms. Let us look at some of the 

 facts which may determine our opinion in the case. 



On the one hand, those forms of animal life which are capable ot 

 easy extension over extensive bodies of land or water, such as the 

 birds, which represent the highest types, physiologically speaking, 

 of life, are distributed in a manner to a large extent co-ordinate 

 with the present arrangement of land and water. The birds seem 

 to have especially become modified and adapted to the present topo 

 graphical features of our earth at a (geologically speaking) recent 

 epoch. On the other hand, those animals of a more lethargic 

 character, or which are prevented by physical environments from 

 extending their range, are grouped entirely otherwise. This is 

 especially the case with the fresh-water animals of various kinds, 

 and notably with the fresh-water fishes. 



If the inhabitants of the fresh waters of the globe are taken into 

 consideration, the several realms we have defined may be combined 

 in quite a curious manner, which entirely contradicts the relations 

 which the present combinations of land and water would suggest. 

 It will then be seen that the inhabitants of the northern portions of 

 the several continents of North America, Europe, and Asia belong, 



