PLANT SOCIETIES 413 



it fills up with strange growths. Pastured wood- 

 lands are usually destitute of underbrush. 



523a. The observation of these little and local plant societies 

 will prepare the pupil to understand the problems involved in the 

 greater societies which comprise the world-floras. Four great types 

 of societies are, — 



Hydrophytio, comprising aquatic floras or those of very humid 



regions ; 

 Mesophytio, comprising mid-condition floras; 

 Halophytic, salt- area floras ; 

 Xerophytic, desert or dry -country floras. 



The best literature upon this subject is Warming's "CEkolo- 

 gisohen Pflanzengeographie," which is now being rendered into 

 English. 



524. The study or science which treats of all 

 these inter-relationships of organisms and their re- 

 lations to environment is knoAi^n as ecology (writ- 

 ten oecology in lexicons). It is the study of the 

 modes of life and habits of animals and plants. 



Suggestions. — Older pupils may be assigned certain local floras 

 to investigate. One may be asked to report what kinds of plants 

 lend the peculiar appearance to an adjacent field, and another may 

 report upon a certain piece of roadside, or upon a lawn, meadow, 

 or garden. Ask a pupil to discover what kinds of plants grow 

 where dandelions, docks, or sorrel do; or what trees grow in woods 

 where basswoods or beeches or oaks or pines predominate. What 

 kinds of plants usually grow in fence-corners? Are they the same 

 kinds that grow in woods ? Are the weeds that grow in meadows 

 or in wheat-fields of the same kind as those in gardens ? It is 

 not necessary that the pupils or the teacher know the names of 

 all the plants. Let the pupils bring specimens. Pupils will en- 

 joy readings from Gaye's "The Grreat World's Farm." More gen- 

 eral discussions of some of the phases of ecology may be found 



