THE FEUIT. 



143 



through the dorsal sutures, when the placentas will be found in the middle 

 of the valves, as in the Violet (fig. 254). In such fruits each valve consists 

 of two half-carpels combined. In the Orchidacere the capsules dehisce 

 in the manner last described, with this further peculiarity that the valves, 

 bearing the placentas in the middle, separate from the midribs or dorsal 

 sutures, leaving these latter attached together at the top, and thus forming 

 an open framework supporting the remains of the perianth. 



In multilocular syncarpous fruits, where the sides and margins of the 

 component carpels are infolded, so as to form partitions or dissepiments, 

 the dehiscence is likewise through the dorsal, or ventral, or through both 

 sutures ; thus dehiscence takes place : a, locuUcidaUy, through the dorsal 

 sutures, so as to open the loculus or cavity of the carpel from behind ; 

 each valve in this case represents two half-carpels (figs. 277, 278) ; or, /3, 

 septicidally , through the septa, so as to isolate the previously combined 

 carpels (fig. 276). Each segment in this case represents an entire carpel. 



Fig. 276. 



Fig. 277. 



Fig. 278. 



Fig. 27fi. Eipe fruit of Geranium, the tailed cocci separating elastically from the carpophore. 

 Fig. 277. Burst capsule of Iri*, with loculicidal dehiscence. 

 Fig. 278. The same in cross section. 



Septicidal and loculicidal dehiscence may occur in the same fruit, as 

 in the Foxglove (Digitalis), the capsule of which first divides into its 

 constituent carpels septicidally, and afterwards each carpel splits loculi- 

 cidally into two valves ; the four valves so produced represent each a 

 half-carpel. 



Both the loculicidal and septicidal modes of dehiscence are sometimes 

 associated with wlmt is termed septifrayal dehiscence. This occurs when 

 the septa or partitions bearing the placentas are broken across ; the effect 

 of this is that the valves break away from the placentas, leaving part or 

 the whole of the latter standing in the centre of the fruit on a kind of 

 column, as in Andromeda, Convolvuhis, Rhododendron, &c. Septifragal 

 dehiscence takes place by itself in the siliques or pods of Crucifera3, where 

 the valves separate from the parietal placentas, leaving them in the centra 

 supporting the ovules (figs. 295 & 296). 



Schizocarps, In some instances, as in Galium, the carpels separate one 

 from the other without opening. In such a case the term schizocarp is 

 employed to designate the whole fruit, while its component carpels are 



