382 BULLETIN OF TIIE 



implied totally distinct life regions, and also a similar division of the 

 two slightly differentiated regions of the North Temperate Realm. 

 For nearly all the species, and hence of course the genera and fam- 

 ilies, of the Arctic Realm, and a considerable percentage of the species, 

 a larger proportion of the genera, and nearly all the families of the 

 Temperate Realm, occur in the northern parts of both the so-called 

 " Neogean " and " Palrcogean Creations." * It is thus seen that the 

 life of the North Temperate Realm differs far more from that of the 

 Tropical Realms than the life of the Old World does from that of 

 the New. Hence the subdivision of the earth's surface into pri- 

 mary ontological regions, according in area with the two primary divis- 

 ions of the land, now so generally adopted, is contrary to the facts, 

 since it wholly ignores the close resemblance of the animals and plants 

 inhabiting the north temperate and arctic regions, and the striking 

 differences between them and those of the intertropical zone. The 

 recognition of a "Nearctic" as contradistinguished from a " Palas- 

 arctic Region " is almost equally arbitrary and at variance with the 

 law of the distribution of life in circumpolar zones. f 



Dana, in his map of the geographical distribution of marine ani- 

 mals,} divided the Tropical Zone into four subzones, — a North and a 

 South Torrid and a North and a South Subtorrid ; and each temper- 

 to require a division of the torrid zone, considered as a climatic zone, into two primary- 

 divisions, with subdivisions of each of several ranks. The south temperate (climatic) 

 zone is similarly divisible, while the Australian Realm, from its isolated position and 

 its remarkable individualization, forms a primary region, with subdivisions of various 

 grades. 



* Dr. Sclater properly observes: "It cannot be denied that the ornithology of the 

 Palsearctic, or great temperate region of the Old World, is more easily characterized by 

 what it has not rather than by what it has. There are certainly few among the groups 

 of birds occurring in this region which do not develop themselves [to an equal or] to a 

 greater extent elsewhere," etc. — Journ. of P roc. /.inn. Soc , Zoology, Vol. II, p. 137. 



t I may here add that the homoge msness of the life of the boreal regions has been 



recognized by a number of recent writers, among whom are Dr. L. K. Schmarda, Dr. Von 



Middendorff, and Professor Huxley, who have each recognized a circumpolar region. 



Professor Huxley has also called attention (see Proc. Zool. Soc. Loud., 1868, pp. 313- 



819) to the wide divergence of the life of the tropics from that of the north-temperate 



19 of even the same continents, and the individualization of Australia and its 



en t islands. He considers that the whole surface of the globe may be "primarily 



subdivided into two principal areas, — a northern and a southern," tor winch be has pro- 



I the names Arclogoea and Notogcea. The latter be has divided into three regions, — 



>. Columbia (= Neotropical Region of Sclater), Australasia, and New Zealand. 



I Rep. on Crust, of U. S. Expl. Exped (Vol II), under Capt. Wilkes. 



