CHAPTER XV 



SEED-DISPERSAL 



150. Reasons for dispersal. If all seeds dropped about 

 the parent plants, there soon would not be room enough 

 for any more to grow, and those that did grow would in- 

 terfere with one another seriously. It is of advantage 

 both to the parent plant and to the young plants for the 

 seeds to be scattered beyond the reach of such rivalry. 

 Accordingly, there are many ways by which seeds are dis- 

 persed, and sometimes they are carried to great distances. 

 When fruits open to discharge seeds, the seeds themselves 

 are scattered; but when fruits do not open, the fruit itself 

 is transported. 



151. Dispersal by discharge. In some plants there is a 

 mechanical discharge of seeds provided for in the structure 

 of the seed-vessel, such 



fruits often being called 



Fio. 248. The fruit of violet dis- 

 charging seeds. After BAIL- 



LON. 



FIG. 249. The pods of a wild bean (Lotus) 

 twisting in discharging seeds. After 

 BAILLON. 



255 



