TRANSPORTATION OF THE FRUIT 



107 



in the Labiatae. The newly formed walls are not always vertical. The 

 fruit of Aeschynomene (Fig. 351) and that of Sophora (Fig. 352) divide 

 transversely into one-seeded joints. 



Special Defensive Provisions. — Concerning the protection of the fruit 

 and seeds, we note that its full accomplishment often calls for other 

 defensive provisions than those against merely mechanical forces, in 

 the form of appendages constituting an armor. These are sometimes 

 an outgrowth from the ovary itself, as in Stramonium (Fig. 282), some- 

 times upon an enclosing calyx (Fig. 283), an enclosing wall consisting 

 of a hollowed branch, as in the prickly pear (Fig. 281), or sometimes upon 



Fig. 279. Cross-section of young fruit of Calesiuni, the cells disappearing except that in which an 

 ovule has been fertilized. 280. Z)20spi/ros, the same. 281. Fruit of OpuH^ia, immersed in prickly end 

 of branch. 282. Fruit of Datura, with prickly ovary. 283. Of i^wmex.with prickly calyx. 284. Of 

 Casiena, with prickly involucre. 285. Three palm-fruits from the same tree, with one or two, u, with 

 none, of the cells aborted. 



an enclosing involucre, as in the chestnut burr (Fig. 284). At other 

 times the protection is secured by developing acrid or otherwise dis- 

 agreeable pericarps, as the husk of the walnut or the pulp of the colo- 

 cynth. These defences may be effective only during the maturing stage, 

 as already pointed out, or their deterrent action may be permanent. 

 In the same direction are to be considered the effects of poisonous 

 principles proper and the inedible nature of a pericarp pending the 

 maturing of the seed, but which afterward becomes edible. 



Transportation of the Fruit. — The transfer of the fruit to the place of 

 germination is secured by methods which for the most part admit of 



