CHAPTER XX 

 ECOLOGY OF FRUITS ; DISPERSAL OF FRUITS AND SEEDS 



234. Subjects of the Chapter. — The ecology of fruits and 

 seeds is concerned mainly with the various means by which 

 seeds are protected from decay or from being destroyed by 

 animals, and the methods by which they are enabled to 

 secure transportation and to become planted in localities 

 suitable for their growth. The latter topic, that of seed 

 distribution, is the one which will be discussed in this 

 chapter. 



235. Dispersal of Seeds. — Seeds are not infrequently 

 scattered by apparatus by which the plant throws them 

 about. More commonly, however, they depend upon other 

 agencies, such as wind, water, or animals, to carry them. 

 Sometimes the transportation of seeds is due to the struc- 

 ture of the seeds themselves, sometimes to that of the 

 fruit in which they are enclosed ; the essential point is to 

 have transportation to a long distance made as certain as 

 possible, to avoid overcrowding. 



236. Explosive Fruits Some dry fruits burst open 



when ripe in such a way as to throw their seeds violently 

 about. Interesting studies may be made, in the proper 

 season, of the fruits of the common blue violet, the 

 pansy, the wild balsam, the garden balsam, the cranes- 

 bill, the herb Robert, the witch-hazel, the Jersey tea, and 

 some other common plants. The capsule of the tropical 



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