THE FRUIT. 201 



(Cerastium.) In the snap-dragon, (Antirrhinum), the sutural 

 rupture is so slight as to produce only points or pores in the 

 upper part of the pericarp. 



Fig. 98. 



Besides these regular forms of valvular dehiscence there is a 

 somewhat anomalous mode of rupture which takes place in a 

 few plants, such for instance as the pimpernell (Anagallis), and 

 henbane (Hyoscyamus), and which is called circurnscissile, 

 (circum around, scindo to cut.) The pericarp of these plants 

 opens by a transverse circular line, following no sutures what- 

 ever but cutting directly across them. It is therefore an 

 anomaly and not a true dehiscence, as we have employed the 

 term. Fig. 98 is the seed vessel of the Hyoscyamus which is 

 ruptured in this manner. The upper part of the pericarp 

 separates like a lid from the lower part. This kind of fruit is 

 called a pyxidium, (pyxis a chest.) 



The pods of some Leguminous plants formed by a single 

 carpel, are divided into several cells, either by the formation 

 of false horizontal partitions, as in some Cassias, or by the 

 contractions of the legume itself, as in Desmodium. Each of 

 these cells contains a separate seed, and the pod when ripe 

 separates by transverse dehiscence at these joints, and falls info 

 pieces. This kind of pod is called a loment, (Fig. 99). This 



18 



