8 Merriam Geographic Distribution of Life. 



Hemsley ............. 1887 .............. Plants ............. Map 



Brendel .............. 1887 .............. Plants ............. Xo map 



Nelson ............... 1887 .............. Birds ............. Xo map 



Schwarz ............. 1888 .............. Insects ............ Xo map 



Bessey ............... 1888 .............. Plants ............. Xo map 



Ridgway ............. 1889 .............. Birds ............. Xo map 



Merriam ............. 1890. . ........... Animals and plants. Map 



Keeler ............... 1891 .............. Birds ............. Map 



The principal bio-geographic divisions that have been recog- 

 nized by a large 'number of writers, and as a rule have been 

 proposed independently and under different names, resulting 

 from the study of different groups, are described in the following 

 synopses, each of which may be regarded as a chronologic syn- 

 onymy of the region to which it refers. 



Arctic Division (Above Limit of Trees). 



An Arctic circumpolar division north of the limit of tree 

 growth was recognized as a distinct region by European writers 

 long before the earliest attempts were made to map the faunal 

 and floral areas of North America.* Hence the following table 

 is necessarily incomplete, since it shows only the extent to which 

 this zone has been recognized by those who have actually defined 

 faunal and floral areas in North America. 



Date Author Name given to reyioit. Study based on 



1820 De Candolle. . . Hyperboreal Region ____ Plants ............. 1 



1822 Schouw ...... Realm of Mosses and Sax- Plants. ... ......... 1 



if rages. 



1830 Pickering ..... Arctic Region .......... Plants ............. 1 



1831 Lesson ....... Arctic Region .......... Birds ............. 1 



1835 De Candolle. . . Arctic Region .......... Plants .......... ... 1 



1836 Meyen ....... Polar Zone ............. Plants ............. 1 



1838 Berghans ..... Realm of Mosses and Sax- Plants ............. 1 



ifrages. 



1843 Hinds ........ Greenland Region ...... Plants ............. 1 



1844 Wagner ...... Polar Province ......... Mammals ......... 2 



* This region, however, is not universally recognized. Wallace and a 

 few others refuse to accept it. Agassiz, Allen, and most botanical writers, 

 on the other hand, regard it as one of the best denned of the primary 

 divisions. An important recent treatise on the subject, from the stand- 

 point of the distribution of mammals, is the following : " Dii'urktixcln- ,W/- 

 reyion Ein Beterag zur geographi&chen Vi'i-lti-fiiimy <l<r 7'//>V/r," by Dr. August 

 Brauer (Zoologisclie Jahrbucher, Abtli. fur. Syst. II I,. Inn., 1SSS, IS9-308, 

 taf. VIII). 



