ITS KINDS. 



317 



617. Septifragal Dehiscence is a modification of either the loculicidal 

 or the septicidal, in which the valves fall away, leaving the dissepi- 

 ments behind attached to the 



axis. Fig. 586 is a diagram 

 representing this in a case 

 of loculicidal opening. Fig. 

 587; from the common Moni- 

 ing-Glory, is this modifica- 

 tion of the septicidal mode. 



618. Instead of splitting 

 into separate pieces, the sutures of the pericarp sometimes open for 

 a short distance at their apex only, as in Cerastium and some other 

 Chickweeds, in Tobacco (Fig. 1050), and in the Primrose (Fig. 

 943) ; or by mere pores, as in the Poppy. The pod of the Snap- 

 dragon opens by the bursting of a hole towards the top of each cell, 

 not corresponding, perhaps, with any suture. Another anomalous 

 mode of dehiscence, namely, the circumcissile, characterizes 



619. The Pyxis or Pyxidium, a pod which opens by a circular hor- 



izontal line cutting off the upper part as a lid. The 

 fruits of the Plantain, Henbane, Amaranth (Fig. 

 575, which is otherwise a utricle), Pimpernel, and 

 Purslane (Fig. 588) -are of this kind. 



620. A Silique is a slender two-valved capsule, with 

 two parietal placenta, from which the 

 valves separate in dehiscence; as in 

 plants of the Cruciferous or Mustard 

 family (Fig. 589), to the fruit of which the term prop- 

 erly belongs. Usually a false partition is stretched 

 across between the two placentte, rendering the pod 

 two-celled in an anomalous manner. 



621. A Sllicle or Pouch is merely a short silique, its 

 length not more than twice its breadth ; as that of Shep- 

 herd's-Purse, Candytuft, &c. 



622. Aggregate Fruits are those in which a cluster of 

 carpels, all belonging to one flower, are crowded on the 

 receptacle into one mass, as in the raspberry and blackberry taken 

 as a whole (Fig. 564), where the constituent fruits, or ripened cai-pels. 



I 



689 



FIG. 586. Septifragal modification of loculicidal, and, 587, of septicidal, dehiscence. 

 FIG. 588. Pyxis or pod of Purslane, the top separating as a lid. 

 PIG. 589. Silique of Cardamine, in dehiscence. 



27*. 



