SCHMIDT: ANIMAL GEOGRAPHY 771 



Wallace at his best. Freed of much of the cumbrous and now obsolete detail 

 that burdens the larger work, the later volume remains a satisfactory and vivid 

 introduction to the study of animal distribution. Unfortunately the long and 

 detailed discussion of the causes of glacial periods rather arbitrarily inserted in 

 this work seems to a modern or skeptical reader incredibly optimistic in its over- 

 simplification of so complex a subject. A completely revised edition of Island 

 Life, retaining as much as possible of Wallace's own writing, is much to be 

 desired. 



In broad outline, the historical development of zoogeography is dominated 

 by Wallace in the generation between the eighteen-fifties and the date of Island 

 Life. This generation concerned itself with an accumulation of the facts of dis- 

 tribution in what might be called "Descriptive Animal Geography"; and with 

 fundamental improvements in the classification of animals. The delimitation and 

 classification of the geographic subdivisions of the earth's surface that seemed 

 to accord best with the facts of animal distribution was perhaps the principal 

 subject of controversy in this period, much of it based on inadequate studies 

 or fields too limited to afford contributions of permanent value. Wallace had 

 adopted the system of regions proposed by Sclater with only a few changes of 

 names. Thomas H. Huxley's entry into the field in a well-reasoned paper on a 

 limited group of birds (1868) must be mentioned, since it suggests an important 

 reclassification and hierarchial arrangement of the zoological regions into three 

 principal realms. An anonymous writer proposed acceptable terms for these — 

 "Arctogaea," to include the Palearctic, Nearctic, Oriental, and Ethiopian 

 regions; "Neogaea" for the Neotropical region; and "Notogaea" for the Aus- 

 tralian. This, with the combination of the Nearctic and Palearctic regions into 

 the Ilolarctic by Heilprin in 1878, leads directly to the modern grouping of 

 realms, regions, subregions, and provinces. 



For all the enthusiasm of Wallace, and in spite of the fact that he and his 

 contemporaries quite correctly assessed the revolutionary importance of the 

 theory of evolution to the concepts of animal geography, the era in which his 

 Geographic Distribution of Animals was the leading work in the field remained 

 essentially involved in these static problems. There was a long series of papers 

 involving the problem of combining the Nearctic and Palearctic regions into an 

 over-all Holarctic region; and whether a distinct Sonoran region should be cut 

 off from the Holarctic to include the southern half of North America. The 

 controversy as to where to draw the line between the Oriental region and the 

 Australian, and especially as to the place of the fauna of Celebes in this scheme, 

 became a zoogeographic classic, which has had renewed attention in the decade 

 of the nineteen-fortics. There was endless report and argument about the degree 

 of relation between one faunal province and another based entirely on the existing 

 faunas, without reference to their origin and history. 



Permanence op Continents 



Darwin and Wallace, with the American geologist Dana to support them, 

 regarded the continents as stable features of the earth's surface, and postulated 

 connections between the continents and between continents and islands only 

 where they exist now, as at Panama; or where there are shallow seas, within 



