3°4 



PLANT LIFE. 



changes produce a fruit like that of the peach or the cherry. 

 The pericarp encloses a single seed 

 with delicate brown seed coats whose 

 protective function has been com- 

 pletely usurped by the stone (fig. 

 352). In other cases, while the 

 inner face becomes stony, the outer 

 becomes fibrous, tough, and dry, as 

 in the almond, walnut, and hickory 

 nut. The outer part in the last even 

 breaks regularly into four pieces. 

 Such fruits furnish a transition from 



Fig. 352. — Fruit of the cherry, 

 halved, e, epidermis of peri- 

 carp ; ?;/, fleshy layer of 

 pericarp ; en, stony layer of 



pericarp; s, seed ; cot, one the most perfect fleshy fruits to the 



of the pair of thickened seed 

 of embr 

 -After Foe 



mbryo. Natural dry fruits. In other cases the placentas 

 become very much enlarged, and the 

 whole of the pericarp becomes fleshy, as in the tomato. In 

 others the outer part of the pericarp is hard and firm, while 

 the inner becomes pulpy, as in the pumpkin and squash. 



412. Accessory fruits. — Parts adjacent to the carpels, 

 either flower leaves or axis or both, stimulated to growth, 

 frequently enter into the formation of 

 fleshy fruits. These may be accompanied 

 by either a fleshy or a dry pericarp. In 

 the wintergreen berry the calyx grows 

 thick and fleshy and surrounds a dry peri- 

 carp, which cracks at maturity (fig. 353). 

 In the strawberry (fig. 287) the torus be- 

 comes greatly enlarged and fleshy, while 

 the minute, one-seeded, dry fruits are 

 scattered over its surface, imitating small 

 seeds. The fig has the same parts, with 

 the torus concave, instead of convex (fig. 

 289). The apple consists of a fleshy torus carrying at its 

 free end the withered calyx and enclosing the tough, thin 



Fig. 353. — Fruit of 

 wintergreen (Ga u I- 

 theria procum- 



bens), halved, show- 

 ing thin (dry) peri- 

 carp, surrounded by 

 thickened fleshy 

 calyx. Magnified 



about 2 diam. 

 Gray. 



-After 



