106 CARPOLOGY: FUNCTIONS AND STRUCTURE OF THE FRUIT 



it is called an Epicarp, and when an endocarp is hard and strong inside 

 of a fleshy layer, like the stone of a peach or the "core" of an apple, it 

 is called a Putamen. 



Modes of Performance of the Fruit Functions. — We shall now consider 

 the maimer in which tlie fonr objects of fructification are accomplished 

 through the modifications effected in each of the floral parts and in 

 the parts adjacent, by fertilization, including such new appendages 

 as are thus caused to develop. 



Growth and Maturity. — The development and maturity of the fruit 

 are eft'ected by the stimulation, through fertilization, of the nutritive 

 functions of the pistil, the torus, adjacent portions of the plant, and 

 through the combined influence of all the flowers, a similar stimulation 

 of all portions of the plant. 



Protection. — So far as the development of a protecting container for 

 the maturing seed is concerned, the object in general demands the 

 development of nothing more than the ovarian wall; but the effects of 

 adnation and the requirements of the other objects result in the exten- 

 sion of this process to various other parts of the flower or even of its 

 supporting parts. The development of such parts in connection with 

 the ovarian walls will therefore receive attention in considering the 

 methods by which such other objects are accomplished. 



The Abortion of Septa and Cells. — It has been stated that not always 

 are all of the ovarian walls involved in fruit development. A gynae- 

 cium possessing several pistils may fail to develop one or more of them 

 in fruit, and when these are adnate into a compound o^'ary, as in Val- 

 lesia, one or more of them may likewise fail to develop. A several- 

 celled ovary, as in Calesium (Fig. 279), may, after the fertilization of 

 one or more ovules in one or more cells, permit the abortion of those in 

 the other cells, the septa of the latter being then crowded against the 

 outer wall by the growing seeds, or even disappearing, so that the fruit 

 will contain a smaller number of cells than the ovary which produced it. 

 The partial obliteration of cells in a similar manner is well shown in the 

 fruit of Diospyros {Fig. 280). 



Mr. J. H. Hart has contributed three fruits taken from one crop of 

 a single plant (Fig. 285, a, b, and c), the first showing the development 

 of all three of the ovarian cells, the others having respectively one and 

 two of these aborted. 



The Development of New Septa and Cells. — x4dditional walls, upon the 

 other hand, may develop during fructification. Datura has a 2-celled 

 ovary (Fig. 221), but a 4-celled fruit (Fig. 223), and this occurs regularly 



