292 



BOTANICAL GAZETTE 



[APRIL 



pidet 



chyma cells. 



very small paren- 



(fig. 21, N), ENDOSPERM (fig. 21, E), and EMBRYO 



(fig. 21, C) present no new features. 



ClTRULLUS VULGARIS SCHRAD. 



Citrullus vulgaris Schrad. (watermelon), now extensively culti- 

 vated in the tropics and warmer regions of the temperate zone, i 

 a native of South Africa. Engler and Prantl emphasize the fact 

 that on its native soil the fruit forms a considerable part of the food 

 of both the natives and the larger animals. This view is substantiated 

 by Livingstone in his Travels in Central Africa. 



The fruit is spherical, or more often ellipsoidal, of a dark green 

 color, frequently mottled with white in ragged, longitudinal stripes 

 several centimeters in width. The rind is firm but not hard, green at 

 the outer surface, white further inward, chang- 

 ing gradually to the glistening pink, red, or yellow 

 inner fruit-flesh, which contains 91-95 per cent, 

 of water. 



f 



—Citrullus 



vulgaris Schrad. 



the numerous white, brown, or black mottled Seed Xl . 



seeds (fig 



They are flat, without a border, 



lustrous, and smooth except when mottled, in which case the} an. 



The great bulk of the fruit is the solid 



slightly rough. 



(figs 





fruit-flesh, and it is this sweet, watery portion that is usually eaten 



and not the rind as in Cucurbna. 



The placentae are beautifully out- 

 lined, the bundles being of a some- 

 what lighter color than the ft* 

 When ver y ripe the flesh nu 

 separate along these hues, W 

 no true cavity is fonnd- * 

 individual cells of the inner flesh 



visible to the naked e> e. 



Fig. 23. — Citrullus vulgaris Schrad. 

 Pericarp in surface view. Epicarp with 

 sto, stoma; hy, hypoderm. X 160. 



are 



Epicarp (ep 



•Instead of 



1. Epicary \*rr 



the true palisade cells there I 



a 



