312 



THE FRUIT. 



597. Till Ffpo, or Gourd-fruit, is also a modification of tlie berry, 

 with a hard rind, which occurs in the Gourd family. The cucum- 

 ber, melon, and squash are familiar illustrations. A Pepo is an 

 indehiscent, externally firm and internally pulpy fruit, composed 

 usually of three carpels, and with an adnate calyx. In the ovary it 

 is either one-celled with three broad and revolute parietal placenta?, 

 or these placenta;, borne on slender 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 (Fig. 5G0, 561). As the fruit enlarges, the seed-bearing 

 placenta? usually cohere with the 

 walls, and the partitions are oblit- 

 erated, giving the appearance of 

 a peculiar abnormal placentation, 

 which only the study of the ovary 

 readily explains. 



598. A Pome, such as the apple, 

 pear, and quince (Fig. 809, 812), 

 is a fruit composed of two or more 

 carpels, either papery, cartilagi- 

 nous, or bony, usually more or less 

 involved in a pulpy expansion of 

 the receptacle or disk, and the 

 whole invested by the thickened and succulent tube of the calyx. 

 It may be readily understood by comparing a ro e-hip with an apple. 

 The calyx makes the princi- 

 pal thickness of the flesh of 

 the apple, and the whole of 

 that of the quince". 



599. The Drupe, or Stone- 



Fruit, is a one-celled, one or 

 two seeded indehiscent fruit, 

 with the inner part of the peri- 

 carp {endocarp, or putameji, 

 588) hard or bony, while the outer (erocarp, ov sarcocarp) is fleshy 

 or pulpy It is the latter which in these fruits so readily takes 

 an increased development in cultivation. The name is strictly 



FIG. 560. Section of the ovary of the Gourd 561. Diagram of one of its constituent carpels. 



FIG 562. Vertical section of a peach. 563 An almond ; where the exocarp, the portion 

 of the pericarp that represents the pulp of the peach, remains thiu and juiceless, and at 

 leDgth separates by dehiscence from the endocarp, or shell. 



