SEXUAL REPRODUCTION. 



223 



In the strawberry (fig. 1 74) the torus becomes greatly enlarged 

 and fleshy, while the minute, one-seeded^ dry fruits are scat- 

 tered over its surface, imitating small 

 seeds. The fig has the same parts, 

 with the torus concave, instead of 

 convex (fig. 176). The apple consists 

 of a fleshy torus carrying at its free 

 end the withered calyx and enclosing 

 the tough, thin pericarp (fig. 194). In 

 the blackberry the receptacle becomes 

 fleshy, and each pistil forms a minute 



fruit like a cherry, adherent to its fig. i92.-Fruit of the cheny, 

 neighbors and to the pulpy torus, ^^i^f ' J,' tsh^'iayerof 

 The raspberry is like it, except that "^^^^^ Jr'setdTiTonl 

 the adherent mass of fruits separates "eaves^o? embryo™ Natural 

 as a cap from a firm torus (fig. 195). =i^^-After Focke. 



310. Multiple fruits. — If the flowers are crowded, either 



dry or fleshy fruits resulting from them may be closely 



crowded at maturity. Under these conditions fleshy fruits 



frequently become adherent, and may thus constitute a 



multiple fruit quite similar in form to the fruit 



^^gjj,^^^ formed by the aggregated carpels of a single 



JmSPi flo^sr. Compare the multiple fruit of the 



mulberry (each section from a separate flower 



whose floral leaves and pistil both become 



pulpy; fig. 196) with such an aggregate fruit 



as the blackberry, in which each section is one 



pistil out of the many belonging to a single 



flower (fig. 19s). The pineapple is similar to 



the mulberry in origin. 



Even more remote parts are stimulated to 

 development by fertilization of the egg. The 

 stem bearing the flower generally grows and 

 becomes stronger, to carry the fruit, especially if large. The 



Fig. 193. — Fruit 

 of wintergreen 

 i^Gaultk-eria 

 pr ocumbens), 

 halved.showiug 

 thin (dry) peri- 

 carp, surround- 

 ed by thiclcened 

 fleshy calyx. 

 Magnified 

 about 2 diam. — 

 After Gray. 



