304 



PLAXr 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 usurjied by the stone (fig. 

 352). In other cases, while the 

 inner face becomes stony, the outer 

 becomes fibrous, tough, and dr\-, as 

 in the almjnd, walnut, and hickory 

 nut. The outer part in the last even 



Fig. 352.— Fruit of the cherry, breaks regularly into four pjieces. 



hah'ed. f, epidermis of peri- , . ^ 



carp; ;</, flesliy layer of Sucll frUltS furUlsll a transition frOUl 



pericarp ; en, stony layer of ,- n i r ■ i 



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



of the pair of thickened seed- 



leaves of embryo. Natural dry fruits. In Other cascs the placcntas 



size. — After Focke. 



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 l)ecomes pulpy, as in tlie piumpjkin and sc]uash. 



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

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

 frequentlv 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 flesh\' and surrounds a drv peri- 

 carp, which cracks at maturity (fig. 3S3)- 

 In the stra«'berry (fig. 287) the torus lie- Fir,. ,5.1 —Fruit of 



- J n , 1 ■, wintergreen (<,„«/- 



comes greatly enlarged and fleshy, while //;,■>-;„ procm,,- 



, . - , , - . /'cv/,(i, halved, show- 



tlie minute, one-seeded, drv fruits are ing thin (dry) pen- 



, . - ... ,, carp, surrounded by 



scattered over its surface, imitating small thickened fleshy 



, rT,i r 1 1 .calyx- Magnified 



seeds. I he fig has the same paits, with aixuit 2 diam,— .Alter 

 the torus conca\e, instead of con\ex (fig. 

 289). The apple consists of a fleshy torus carr\ung at its 

 free end the withered cal)x and enclosing the tough, thin 



