I4 PLANT BIOLOGY 



falls largely because the foliage ripens more gradually 

 and persists longer in such seasons. It is probable that 

 the autumn tints are of no utility to the plant. Autumn 

 colors arc not caused by frost. Because of the long, dry 

 falls and the great variety of plants, the autumnal color of 

 the American landscape is phenomenal. 



Ecology. The study of the relationships of plants and 

 animals to each other and to seasons and environments is 

 known as ecology (still written (ecology in the dictionaries). 

 It considers the habits, habitats, and modes of life of liv- 

 ing things the places in which they grow, how they 

 migrate or are disseminated, means of collecting food, 

 their times and seasons of flowering, producing young, 

 and the like. 



SUGGESTIONS. One of the best of all subjects for school instruc- 

 tion in botany is the study of plant societies. It adds definiteness 

 and zest to excursions. 7. Let each excursion be confined to one 

 or two societies. Visit one day a swamp, another day a forest, 

 another a pasture or meadow, another a roadside, another a weedy 

 field, another a cliff or ravine. Visit shores whenever possible. 

 Kach pupil should be assigned a bit of ground say 10 or 20 ft. 

 square for special study. He should make a list showing (i) 

 how many kinds of plants it contains, (2) the relative abundance 

 of each. The lists secured in different regions should be com- 

 pared. It does not matter greatly if the pupil does not know all 

 the plants. He may count the kinds without knowing the names. 

 It is a good plan for the pupil to make a dried specimen of each 

 kind for reference. The pupil should endeavor to discover why 

 the plants grow as they do. Note what kinds of plants grow next 

 each other ; and which are undergrowth and which overgrowth ; 

 and which are erect and which wide-spreading. Challenge every 

 plant society. 



