298 



THE FRUIT. 



sort are PYREN^ ; and the fruits are dipyrenous, tripyrenous, 

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

 pyrenae. When the sarcocarp is thin and dries up at maturity, 

 these p}Tenae pass by gradations into nuculae (5G'J) 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)- <>f 

 parchment-like or (in Hawthorns) bony texture. 



enclosed in flesh which morphologically belongs 

 to adnate calyx and receptacle ; as may lie ap- 

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

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

 whole flesh is calyx or hypanthium (39.")) ; in the 

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

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

 In the fruit of Hawthorns, the carpels become bony 

 pyren;e (574), and so the fruit is drupaceous, is 

 indeed nothing more than a syncarpous drupe. 

 In Eriobotrya, or Cumquat, the carpels becoming 

 veiy thin and membranaceous, the pomaceous 

 fruit is in fact a kind of berry. 



576. The I'epo, 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 Cucurbitacese, 

 llesh}" internally and with a hard 

 or firm rind, 11 or part of which 

 is referable X) the adnate calyx 

 completel 1 incorporate with the 

 ovary. This is either one-celled 

 with three broad and re volute 

 parietal placenta 1 , or these pla- 

 centae, borne on thin dissepiments, 

 meet in the axis, enlarge, and 

 spread, unite with their fellows 

 on each side, and an- rellccted to 

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

 the fruit enlarges, the seed-bearing placenta- usually cohere 

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



FI(;. 641. Pome or apple in transverse section. C.rj. (.miner in vertical section : the 

 inner flesh answering to disk in tin- apple and pear is liere wanting. 



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

 carpels. 



I'll 



