xxxviii BOTANY. 



and the formation of a soft and juicy pulp; (3) the hardening of 

 some portions of the ovary wall by the development of stony tis- 

 sue; (4) the thickening and growth of the adnate calyx or recep- 

 tacle, etc. etc. 



Where the ripening walls remain thin and become dry the fruits 

 are said to be dry, e.g., in the bean ; -where they become thickened 

 and more or less pulpy they are fleshy, e.g., the peach. These 

 terms are used also -when the fruit includes an adnate calyx or 

 receptacle. 



In many fleshy fruits (developed from carpels) the inner part of 

 the pericarp- wall is hardened ; the two layers are then distinguished 

 as exocarp andendocarp; when there are three layers the middle one 

 is the mesocarp. 



Dehiscence. — The opening of the fruit in order to permit the 

 escape of the seeds is called its dehiscence, and such fruits are said 

 to be dehiscent; those which do not open are indehiscent. In 

 fruits developed from single carpels dehiscence is generally through 

 the ventral or dorsal suture, or both; in those developed from 

 compound pistils the partitions may split, and thus resolve each 

 fruit into its original carpels {septicidal dehiscence) ; or the dorsal 

 sutures may become vertically ruptured, thus opening every cell 

 (loculus) by a vertical slit (hculiddal dehiscence, Fig. XXXIX, 3). 

 Among the other forms of dehiscence only that called dreumcis- 

 dle, Fig. XXXIX, 3, and the irregular need be mentioned; in 

 the former a transverse slit separates a lid or cap, exposing the 

 seeds; in the latter an irregular slit forms at a certain place, and 

 through this the seeds escape. 



Kinds of Fruits. — The principal fruits may be distinguished by 

 the brief characters given in the following table : 



A. MONOGYNCECIAL FEUITS, 



formed by the gynoecium of one flower. 



I. Capsulary fruits.— The Capsules. — Dry, dehiscent, formed 

 from one pistil (Fig. XXXIX.) 

 1. Monocarpellary. 



(a) Opening by one suture— e.g., Caltha. Follicle. 

 (i) Opening by both sutures— e.g.. Pea . Legume. 



