r 
Phytogeographie regions of North America. 341 
The foregoing list shows that there is a connection between the antarctic 
and andine floras, a connection that is more evident when the comparison is 
made to include Antericin plants not extending northward to Mexico. The 
most pregnant fact, according to HEMSLEY, is that the genera are almost without 
exception much more strongly developed in America than they are in Australasia 
and the antarctic islands. But if we take the vegetation generally of the southern 
coldest zone and regions, the preponderance of what may be called American 
types, in contradistinction to those which are more fully represented in the 
Australian region is not so great. 
Chapter V. North American Phytogeographic Classifications, 
Rehearsing the classifications which have been made of the phytogeographic 
regions of North America, one of the first most consistent attempts is presented 
in MEYEN’S Grundriss der Pflanzengeographie (1836),') translated by MARGARET 
JOHNSTON into English and published by the Ray Society in 1846. Meyen 
divides the horizontal range of vegetation into zones and the phytogeographic 
regions are consciously included in these world encircling zones, viz., equatorial 
zone; tropic zone; sub-tropic zone; warmer temperate zone; colder temperate 
zone; sub-arctic zone; arctic zone, and polar zone. The vegetation of North 
America is referred in the most general way to these several zones, which are 
more or less determined by the temperature of the air and fot by the phy- 
siographic character of the country. His division based on the vertical range 
of vegetation need hardly be referred to here. 
Under the notion of separate centers of development, the most important 
classification of the land areas of the globe into vegetation regions is that of 
GRISEBACH. By this writer twenty-four regions are recognized, the following 
only concerning this discussion, viz., 
I. Arctic Region. 
en .. u“ of the Western Continent. 
. Prairie R 
ee Californian Const Region. 
XV. Mexican Region. 
XVI. West toltan Raser 
XVH. Cisequatorial South American Region. 
ENGLER°) divides the surface of the globe into four principal realms (Floren- 
reiche), each of these into regions and each region into provinces, according 
to his theories of general development and migration. The regions of the 
continent of North America come under two realms. The regions ad provin- 
ces where published by this well known author in a new form in ups Bien 
p- 344). 
ı) Confer the Bibliography p. 46—51. 
2) ENGLER, A.: Versuch einer Entwicklungsgeschichte II: 334—347; also en nn 
89. H 
The Metaspermae of the Minnesota Valley, 1892, p. 589 
