374 GENERAL BIOLOGY 



Study each species as to its more important ecological 

 characters and record these characters briefly in a table 

 prepared with the following headings : 



Name. 



Duration (annual, biennial, perennial). 



Increase (aside from seeds, by offsets, stolons, tubers, etc.) 



Social habit (solitary, commingling, copse forming, cover 

 forming) . 



Growth habit (scape, rosette, wand, bush, crown. If 

 not erect, trailing, twining, climbing or epiphyte, parasite, 

 subterranean, etc.) 



Rooting in (topsoil, subsoil, deep soil, rock crevices, rotten 

 wood, etc.) 



Favorite situation. 



Favorite exposure. 



Season of maximum vegetative activity (spring, early 

 summer, late summer). 



Write the names in the first column by groups, as 

 follows : 



i trees 

 shrubs 

 herbs 

 Pteridophytes 

 Bryophytes 

 Thallophytes. 



The record. — After the table is completed (the entire 

 green plant population of the area selected being included 

 therein), then wTite out briefly your interpretation of the 

 facts, as to the relative dominance of each ecological 

 characteristic, and possible reasons therefor. 



Adjustments in place may be further illustrated by the 

 zonal distribution of aquatic seed-plants, indicated at the 

 right in figure 224. This represents an inviolable order; for 

 the shoreward types are capable of shutting out the light 



