156 VEGETABLE ORGANOGRAPHY. 



The most simple, but not most frequent case is that 

 which is called Septicidal dehiscence, because it takes 

 place in the partitions which seem to split in two : there 

 is a particular case of this, which T name Dehiscence 

 by Separation ; it consists in the carpels being so 

 slightly joined together, that they separate from one 

 another at maturity, forming so many distinct bodies, at 

 first closed, afterwards opening, by one of the systems 

 mentioned above, in solitary carpels ; thus, the carpels of 

 the Colchicaceas separate at maturity, and open in the 

 manner of follicles by a fissure along the ventral suture, 

 which in the entire fruit was central. Thus the carpels 

 of Hermannia laevigata separate at maturity, and each 

 of them opens by its two sutures, as most legumes. 



This dehiscence is also modified by the existence or 

 non-existence of a central axis : when this does not 

 exist, it may happen, either, — 1st, that the carpels 

 detach themselves entirely from one another, leaving the 

 centre of the fruit void, as we see in Colchicum ; or, 2d, 

 that the extreme portions of the partitions, which bear 

 the placenta), may be so united together as not to 

 separate, then the rupture takes place along the placenta; 

 the carpels open by leaving in the centre a false semini- 

 ferous axis, formed by the intimate union of the inner 

 margins and placentas ; this takes place in the Balsam. 

 When the axis exists, the same two cases may happen : 

 sometimes the carpels, on detaching, carry with them 

 the placenta?, and leave the axis bare, as in the Malva- 

 ceae, Euphorbiaceae, &c. Sometimes the placentas may 

 remain united to the axis, and the rupture may take 

 place along the partitions; but I do not know an ex- 

 ample of this mode of dehiscence, and, in general, it is 

 not always easy to distinguish the case where the 

 apparent axis is formed by the placentas alone, or by the 

 placentas united to the axis. 



