298 



THE FRUIT. 



sort are PYREN.E ; and the fruits are dipyrenous, tripyrenous, 

 tetrapyrenous, &c., according as they contain two, three, or four 

 p}Tenae. When the sarcocarp is thin and dries up at maturity, 

 these pyrenae pass by gradations into nuculae (569) or nutlets: 

 hence pyrenae are not uncommonly in English descriptions called 

 nutlets or nucules. 



575. The Pome (Fig. 641, 642) is the name of the apple, pear, 

 and quince. These are fleshy fruits, composed of two to 

 several carpels (rarely by abortion only one) , of 

 parchment-like or (in Hawthorns) bony texture, 



enclosed in flesh which morphologically belongs 

 to adnate catyx and receptacle ; as may be ap- 

 prehended b}- comparing a rose-hip (Fig. 407, in 

 flower) with an apple or a pear. Of the quince, the 

 whole flesh is calyx or hypanthium (395) ; in the 

 apple and pear, the inner or core-portion of the 

 flesh is of the nature of disk, investing the carpels. 

 In the fruit of Hawthorns, the carpels become bony 

 pyrenae (574), and so the fruit is drupaceous, is 

 indeed nothing more than a s}'ncarpous drupe. 

 In Eriobotrya, or Cumquat, the carpels becoming 

 very thin and membranaceous, the pomaceous 

 fruit is in fact a kind of berry. 



576. The Pepo, or Gourd-fruit (Fig. 643), of which the gourd 

 and squash are the type, and the melon and cucumber equally 



familiar illustrations, is the char- 

 acteristic fruit of Cncurbitaceae, 

 fleshy internally and with a hard 

 or firm rind, all or part of which 

 is referable to the adnate calyx 

 completely incorporate with the 

 ovary. This is either one-celled 

 with three broad and revolute 

 parietal placentae, or these pla- 

 centae, borne on thin dissepiments, 

 meet in the axis, enlarge, and 

 spread, unite with their fellows 

 on each side, and are reflected to 

 the walls of the pericarp, next which they bear their ovules. As 

 the fruit enlarges, the seed-bearing placentae usually cohere 

 with the walls, and the partitions are obliterated, giving the 



FIG. 641. Pome or apple in transverse section. 642. Quince in vertical section: the 

 inner flesh answering to disk in the apple and pear is here wanting. 



FIG. 643. Section of the ovary of the Gourd. 644. Diagram of one of its constituent 

 carpels. 



