ITS DEHISCENCE. 323 







whole, of the nutritive matter collected in the pericarp is absorbed 

 by the placenta (543) and conveyed to the seed ; where the por- 

 tion which is not consumed in its growth is stored up, either in the 

 embryo or around it, as a provision for its future development in 

 germination. 



592. Certain fruits remain closed and entire at maturity, as the 

 acorn, apple, grape, &c. ; when they are said to be indehiscent. 

 Others separate (wholly or partially) into several pieces, and dis- 

 charge the seeds ; sometimes bursting irregularly, but commonly 

 opening in a uniform and regular manner for each species ; these 

 are said to be dehiscent. 



593. Dehisceiice, when regular and normal, takes place in a ver- 

 tical direction, by the opening of one or both sutures (541), or by 

 the disjunction of confluent parts (546). The pieces into which a 

 dehiscent pericarp separates are called its valves. 



594. A simple carpel dehisces either by the opening of the ven- 

 tral suture, as in the Columbine, the Peony, &c. ; or by the dor- 

 sal suture also, as in the Pea and Bean. 



595. The dehiscence of a pod which results from the union of 

 two or more carpels may take place by the separation of the con- 

 stituent carpels from each other, and by the opening of the ventral 

 sutures, as in the Colchicum (Fig. 1115), Rhododendron (Fig. 793), 

 and in the diagram (Fig. 435). In this case, the pericarp splits 

 through the dissepiments ; whence the dehiscence is said to be sep- 

 ticidal. Sometimes the carpels, although separating from each 

 other in this manner, remain closed or indehiscent, as in the Mad- 

 der (Fig. 748), the Vervain (Fig. 869), &c. : the separable car- 

 pels are often termed cocci ; and the fruit is said to be dicoccous, 

 tricoccous, &c., according to their number. 



435 436 



596. Otherwise, the dehiscence may take place by the dorsal 



FIG. 435 -437. Diagrams of the dehiscence of capsules (horizontal sections) : 435, the sep" 

 ticidal ; 436, the loculicidal ; 437, the septifragal. 



