ITS KINDS. 



317 



617. Scptifragal Dehiscence is a modifica ion 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 Morn- 

 ing-Glory, is Phis modifica- 

 tion of the septicidal mode. 



G18. Instead of splitting 5S7 



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 lyxis 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 placenta?, rendering the pod 

 two-celled in an anomalous manner. 



621. A Silicle 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 Fl'UitS are those in which a cluster of 

 carpels, all belonging to one flower, are crowded on the 589 

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

 as a whole (Fig. 564), where the constituent fruits, or ripened carpels, 



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

 FIG. 688. P\ xis or pod of Purslane, the top separating as a, lid. 

 IIG. 589 Silique of Cardamine, iu dehiscence. 



27* 



