SPERM ATOPHYTES : ANGIOSPERMS 



211 



FIG. 183. The two figures to the left are seeds of violet, one showing the black, hard 

 testa, the other being sectioned and showing testa, endosperm, and imbedded 

 embryo; the figure to the right is a section of a pepper fruit (Piper), showing 

 modified ovary wall (po, seed testa (sc), nucellus tissue (p), endosperm (en), and 

 embryo (em). After ATKINSON. 



hair on the seeds of milkweed, cotton, or fireweed (Fig. 

 185). For a fuller account of the methods of seed-dispersal 

 see Plant Relations, Chapter VI. 



FIG. 184. A winged seed of Bignonia. After STRASBURGER. 



116. The fruit. The effect of fertilization is felt beyond 

 the boundaries of the ovule, which forms the seed. The 

 ovary is also involved, and becomes more or less modified. 

 It enlarges more or less, sometimes becoming remarkably 

 enlarged. It also changes in structure, often becoming 

 hard or parchment-like. In case it contains several or 

 numerous seeds, it is organized to open in some way and 

 discharge them, as in the ordinary pods and capsules (Fig. 

 185). In case there is but one seed, the modified ovary 



