CORRESPONDENCE OF CLIMATIC COMMUNITIES 313 
a forest community. In the savanna or prairie climate the marsh 
margin thicket may become a climatic thicket or forest margin. In the 
savanna or prairie climate the communities of all the various soils and 
the low prairie community may converge to the prairie climate com- 
munity, or to the forest community as is shown below for the forest 
climate. In the forest climate and locally in the savanna climate the 
communities of all the various soils pass through a thicket community 
stage (T), related to a climatic forest. The thicket communities of all 
the dry soils are related to the forest margin thicket community of the 
savanna climate. 
I. CORRESPONDENCE OF COMMUNITIES OF DIFFERENT PARTS OF 
THE WORLD (55) 
The botanists have abundant evidence for the correspondence of 
the formations of similar climates (58a). The vegetation of different 
parts of the world which have similar climates is similar and the plants 
though usually belonging to different taxonomic groups are similar in 
growth, form, and appearance. Correspondence and similarity of 
vegetation is not limited to the climatic or extensive formations, but 
applies also to strictly local situations wherever the physical conditions 
are similar. On the animal side we have less trustworthy evidence of 
similarity or correspondence. If the physiological similarity occurs in 
the same community, due, as has just been stated, to selection of habitat 
and modification of behavior, we conclude that it occurs in all communi- 
ties occupying similar conditions and that similar situations in different 
parts of the world have physiologically similar communities, and identical 
situations approximately identical communities. 
The direct evidences for the correspondence of formations in different 
parts of the world are as follows: (a) the existence of identical or closely 
corresponding species has long been known to naturalists (3, 199, 192); 
(0) similarity of physiological life histories of many species is well known, 
as, for example, corresponding species in the United States and Europe 
or Japan, and a general concentration of breeding in the rainy season in 
all arid climates, etc.; (c) certain animals in similar environments in 
different parts of the worid appear from the accounts of naturalists to 
behave alike with reference to the physical condition of different parts 
of the day, year, and different weather. For example, it appears that 
there is a close physiological and ecological similarity between certain 
antelopes of the savannas of Africa and certain savanna kangaroos of 
Australia (200). In other words certain kangaroos are ecologically 
