ANxVlVERSAEY ADDRESS OF THE PEESIDENT. 69 



Various other schemes of regional subdivision have been proposed, 

 but it is unnecessary to notice all. I have already alluded to the 

 most important, that of Professor Huxley, who, on a general survey 

 of terrestrial vertebrates*, proposed four primary distributional 

 provinces, viz. : — 



1. Novo-Zelanian (I^ew Zealand). 



2. Australian. 



3. Austro- Columbian (N"eotropical of Sclater, South America). 



4. Arctogcean (Palsearctic, Ethiopian, Oriental, and Nearctic 

 united) . 



By far the most important work on the subject yet produced is 

 "Wallace's ' Geographical Distribution of Animals ' (2 vols., 1876), in 

 which the author adopts Sclater's regions in their entirety for all 

 terrestrial and freshwater forms of animal life. In this work lists 

 of the families of Mammals, Birds, Eeptiles, Batrachians (or 

 Amphibia), Freshwater Fishes and diurnal Lepidoptera found in each 

 region are given, and also of the genera of mammals and some 

 birds (Passeres, Picarise, Psittaci, and Accipitres). Numerous details 

 are added relating to other terrestrial animals, but the regional 

 arrangement is mainly founded on the birds of the orders named, and, 

 as is especially stated, on Mammalia f. With the question whether 

 the mammals quite agree with the classification proposed I shall deal 

 presently ; meantime it should be mentioned that Wallace, amongst 

 the reasons given for adopting the regions named, assigns a high 

 rank to the convenience of employing large subequal divisions. 



There is one aspect of the whole question to which attention 

 must be drawn. No one doubts that the present form of the great 

 land- tracts extends back with but trivial modification to Pliocene 

 times at least, the only important changes of later date being the 

 opening of Behring's Straits, and severance of America from Asia, 

 the separation from continents of certain continental islands, such as 

 Great Britain and Ireland, Sumatra, Java, and Borneo, Ceylon, &c., 

 and perhaps the reunion of North and South America. The 

 changes since Miocene, and perhaps since Eocene, times have 

 probably been neither very extensive nor very numerous. If, 

 however, the principal divisions of the earth have remained the 

 same or nearly the same for a longer period than the existence of 

 most living genera of Yertebrata, the animals inhabiting those 



* P. Z. S. 1868, p. 316 ; Q. J. G. S. xxvi. p. Iv. 

 t ' Geogr. Distrib.' i. p. 57. 



