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A TEXTBOOK OF THEORETICAL BOTANY 



which is, of course, traceable in the long run to pollination. An insufficient 

 amount of evidence is available for detailed discussion. 



Fig. 1407. — Laportea moroides. A, Female flower. B, After 

 fertilization. Pedicel and upper perianth segment 

 swelling. C, Later stage. The cell arrangement in the 

 swollen pedicel indicated by wa\y lines. Pedicel 

 stippled. Perianth segments hatched. {After Goebel.) 



Fruit Dispersal. The dispersal of fruits follows much the same lines 

 as the dispersal of seeds already described, except that mechanisms assisting 

 dispersal are produced by carpellary or other structures, not by the testa. 

 One might imagine that in dehiscent fruits the onus of dispersal would 

 naturally fall upon the liberated seeds and that therefore fruit dispersal 

 as such would be limited to akenes, but this is not entirely so, although 

 true up to a point, for there are fruits in which dehiscence is delayed and 

 the fruit is dispersed by one means or another, especially by animals, 

 before the seeds are shed. It is true, however, that many-seeded fruits 

 which are furnished with special means of fruit dispersal are generally 

 indehiscent. When one considers the circumstances of dispersal and the 

 great advantages of numbers and of lightness, it seems reasonable to sup- 

 pose that dispersal of seeds is more likely to reach high efficiency and that 

 fruit dispersal is a second-best. 



Wind Dispersal. There are a very large number of wand-dispersed 

 fruits of the akene type, in which either flat expansions or wings or plumes 

 are employed to catch the wind. Not all fruits with such forms are normally 

 wind-distributed, one exception being Begonia. Its capsules have three 

 conspicuous wings at the angles but they dehisce and release a horde of 

 minute seeds without becoming detached. 



