380 GEOGRAPHIC DISTRIBUTION OF LIFE IN NORTH AMERICA. 
PRAIRIE DIVISION. 
A few botanists, influenced by the widely different aspects of nature 
resulting from the presence or absence of forests, have recognized a 
‘“« Prairie region,” as one of the great floral divisions of North America. 
It was first proposed by Pickering, in 1830. Pickering named it the 
‘“‘ Louisianian flora,” and gave its boundaries as the Mississippi on the 
east and the Rocky Mountains on the west. Hinds described it, in 
1843, as “a peculiar tract inclosed by the vast forests of North 
America.” He named it the “ Prairie region,” and said it extended 
“from within a hundred miles of the west bank of the Mississippi to 
the Rocky Mountains, stretching north to 54° north latitude, and again 
only bounded on the south by the wooded country of the Texas and the 
Mexican Sea.” 
Cooper, in his paper on the distribution of forests (in 1859), named 
it the Campestrian province. It was recognized by Brown in 1870, by 
Porter in 1874, and by Engler in 1882. 
RECAPITULATION. 
It is seen that a number of zodlogists and botanists, basing their 
studies on widely different groups, and as a rule ignorant of the writings 
of their predecessors, have agreed in the main in the recognition of at 
least seven life areas in extra-tropical North America, namely: (1) An 
Arctic area north of the limit of tree growth; (2) a boreal trans-con- 
tinental coniferous forest region; (3) an Atlantic or Eastern wooded 
region stretching westward from the Atlantic to the Great Plains; (4) 
a central or middle region, reaching from the plains to the Sierra 
Nevada and Cascade Mountains; (5) a Pacific or California division, 
covering the area between the east base of the Sierra and the Pacifie 
Ocean; (6) a Louisianian or Austro-riparian division, comprising the 
South Atlantic and Gulf States south of latitude 36°; (7) a Sonoran 
division, occupying the high table-land of Mexico and stretching north- 
ward over the dry interior far enough to include the southern parts of 
California, Nevada, Arizona, New Mexico, and Texas. 
With or without reference to the above principal divisions, it has 
been recently the custom of zodlogists, particularly ornithologists, to 
sub-divide the eastern United States and Canada into several minor 
areas or “faunas,” as follows: (a) Floridian; (b) Louisianian; (c) Caro- 
linian; (d) Alleghanian; (e) Canadian; (f) Hudsonian; and (q) Aretie. 
Of these the Canadian and Hudsonian form a part of the “Boreal” 
region above mentioned, and the Floridian and Louisianian together 
make up the “‘ Austro-riparian” division, leaving only the Carolinian and 
Alleghanian for the so-called ‘“ Kastern province” to rest on. The true 
relations of these zones will be explained later. 
