LOCALITIES STUDIED 51 
have not only this, but we must make a still more important choice, 
namely, that of the locality of study. To make this selection one must 
possess a good knowledge of animal environments, such as we have 
touched upon in the preceding pages. 
I. BASIS OF SELECTION AND SUBDIVISION 
Such knowledge can be acquired from texts of physiography and 
plant ecology, and from special works on the area at hand. The basis 
EEE] Coniferous Forests 
GSES Deciduous Forests. 
(=e Plans. 
Fic. 8.—Map showing the location of the plains, savanna (prairie), and forest 
regions of North America, with area of special study inclosed in rectangle (from 
Transeau after Sargent). 
of selection is either that of age or of present conditions, or both. The 
points selected for study are called stations. Stations are subdivided 
on the basis of plant and animal habitats into substations. The sub- 
stations may represent either formations or divisions of formations. 
For example, a station like Wolf Lake may be divided into sandy 
shore substation, vegetation of open-water substation, and embayment 
substation. 
2. ENUMERATION OF STATIONS—GUIDE 
Tn the study at hand we have made use of a large number of stations 
which are enumerated below and are referred to in the text. The list 
