306 DEHISCENCE OF ONE-CELLED COMPOUND FRUITS. 
centation, the dehiscence may take place either through the 
confluent margins or sutures of the adjoining carpels, so that 
each placenta is divided into its two lamellz, as in the species of 
Gentian (fig. 680), in which case the dehiscence is analogous to 
the septicidal form, and each valve, therefore, represents one of 
the component carpels of the fruit ; or the dehiscence may take 
place through the dorsal sutures, as in the Heartsease (fig. 681), 
in which case it is analogous to the loculicidal form of dehis- 
cence, and each valve is composed of the adjoining halves of 
two carpels. These forms may be readily distinguished by the 
varying attachment of the placentas and seeds in the two cases ; 
thus, in the former instance, each valve will bear the placentas 
and seeds on its two margins (fig. 630), and the valves are said 
Fic. 680. Fic. 681. Fic. 682. Fie, 683. 
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Fig. 680. One-celled fruit of a species of Gentian 
dehiscing in a septicidal manner.——Fig. 681. 
One-celled fruit of Heartsease (Viola tricolor’), 
dehiscing in a loculicidal manner.——Fig. 682. 
Fruit or siliqua of the Wallflower, showing the 
separation of two valves from the replum. 
Fig. 683. Fruit (ceratium) of Celandine (Chelido- 
nium majus), with the valves separating from 
the placentas, 
to be placentiferous at their borders ; in the latter, the placenta 
and seeds will be attached to the centre of each valve (jig. 
681), and the valves are then said to be placentiferous in their 
middle. It sometimes happens, as in the frnit of the Cheli- 
doniwm (fig. 683), and Wallflower (jig. 682), that the placentas 
bearing the seeds remain undivided, and the valves break away 
from them, so that they are left attached to a frame or replum 
(page 277). 
In compound fruits with a free central placentation, the 
same forms of dehiscence occur as in those with parietal pla- 
centation, but here it is difficult in many cases to speak 
positively as to the nature of the dehiscence. from the absence 
of seeds or dissepiments upon the valves. The means usually 
adopted in such cases is to count the number of the valves and 
