DIV. n 



SPERM ATOPHYTA 



583 



of the succulent receptacle bearing the small yellow nut-like fruitlets. In the 

 Apple the core only is the fruit, the succulent tissue being derived from the 

 hollowed floral axis surrounding and fused with the carpels. In the Rose there is 

 similarly a collective fruit, the fruitlets being the hard nutlets enclosed by the 

 succulent receptacle (Fig. 569). In the case of fruits resulting from syncarpous 

 gynaecea the further development of the wall of the ovary as the PERICARP has to 

 be especially considered. The outermost, middle, and innermost layers of this are 



I 



Fir;. 570. Modes of dehiscence of capsular fruits. A, B, Capsule of Viola tricolor before and after 

 the dehiscence; C, poricidal capsule of Antirrhinum majus (magnified); D, E, pyxidium of 

 Ancujdllis arvensis before and alter dehiscence. 



distinguished as EXOCARP, MESOCABP, and EXDOCARP respectively. According to 

 the nature of the pericarp the forms of fruit may be classified as follows : 



1. A fruit, with a dry pericarp, which opens when ripe, is termed 

 a" CAPSULE (Fig. 570). 



When dehiscence takes places by a separation of the carpels along their lines of 

 union the capsule is SEPTICIDAL ; when the separate loculi open by means of a 

 longitudinal split, it is termed LOCULICIDAL, and when definite circumscribed open- 



Fio. 571. Dry indehiscent fruits. A, Xut of Fumaria 

 officinalis (x C). B, Achene of Fagopyntm esculent urn 

 (x 2). (After DUCHA.RTRE.) 



FIG. 572. Schizocarp of Galium, 

 mottugo. (x 6. After Du- 



CHARTRE.) 



ings are formed, it is termed PORICIUAL. As special types of frequent occurrence 

 may be mentioned : the FOLLICLE, which is a capsule developed from a single 

 carpel and opening by separation of the ventral suture, e.g. Aconitum (Fig. 644) ; 

 the LEGUME or pod, which differs from the follicle in dehiscing by both ventral 

 and dorsal sutures, e.g. Laburnum (Fig. 711). 



2. DRY INDEHISCENT FRUITS have a dry pericarp which does 

 not open at maturity. Those with a hard pericarp are termed NUTS, 

 e.g. Hazel-nut, Lime (Fig. 669), Helianthiis (Fig. 784 A). 



