ORIGIN AND DEVELOPMENT OF SOME COMMON FRUIT. 



Fig. 1528.— Comparative few of fruits. A, Strawberry ; B, 

 Raspberry ; C, Mulberry. 



ries — strawberry, raspberry and mulberry. 

 The mulberry, to a superficial observer, 

 may look not unlike the raspberry or the 

 blackberry. We see, however, that each 

 little fruit in a raspberry or blackberry 

 is tipped with a single thread — the re- 

 mains of the upper part of the pistil ; 

 but each little fruit in the mulberry is 

 tipped with more than one thread, and 

 there are lines crossing the fruitlet. If 

 we cut longitudinal sections of these 

 berries, we shall have before us such 

 appearances as are shown in Fig. 1529. 

 From these figures and from a study 

 of the development of the fruits, it can 

 be seen that the fruit of the strawberry 

 is a fleshy stem or axis with the small 

 dry pistils in its surface ; the fruit of 

 the blackberry is composed of many 

 fleshy pistils attached to a slightly 

 fleshy axis ; the fruit of the raspberry, 

 as ready for market, is like that of the 

 blackberry except that the pistils of 

 which it is composed are separated 



from the central axis ; while the 

 fruit of the mulberry consists of a 

 whole branch, all parts of the flow- 

 ers of which have developed over 

 into fruit. Each little fruit in a 

 mulberry has a central part which 

 is the pistil containing seeds, and 

 enveloping this pistil are four 

 fleshy calyx-lobes. Each little 

 fruit is attached by a short stem to the 

 central larger stem ; so that the mul- 

 berry is made from a whole group 

 of female flowers including the stems 

 of these flowers. The mulberry is 

 therefore the same kind of fruit as a 

 naked ear of corn. In the ear of corn, 

 however, the pistils are not united with 

 the calyx as in the mulberry. 



Fig. 1529. — View of fruits in section. A, Straw- 

 berry ; B, Blackberry; C, Raspberry; D, Mul- 

 berry. Dotted line in A and B show where the 

 fruit separates from the axis. 



Fig 1530. Pineapple. (Ananas sativus). A, head of 

 flowers ; B, head of fruit ; C, single flower, showing 

 calyx and corolla; D, flower in longitudinal section ; 

 E, petal and stamen ; F, pistil and calyx. 



In the pine apple, Fig. 1530, the 

 flowers are grouped in a head as in the 

 flowers of the red clover. There is a 

 central s*tem from which the flowers 

 branch off as in the mulberry, but in the 

 pine apple, in addition to the various 

 parts of the flower, there are leaves in- 

 terspersed, a leaf just below each flower. 

 When the pine apple ripens, all parts 

 become fleshy and fuse together, pistils, 

 stamens, corollas, calyxes, leaves and 

 plant stem, all uniting to make this deli- 

 cious fruit. 



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