>9°9 



BARBER 



-FRUITS AND SEEDS OF CUCURBITACEAE 



293 



The outer 



tar, 33 p. in thickness, of cells often broader than high. 

 Z is very thick, the thickening running down on the rad.d wall , 

 In surface view the middle lamella is visible and the hypoderm ts 

 quite evident through the thick-walled but transparent ePJ^P- 



The ovary and very young fruit bear jointed hairs, winch o ten 



reach a length of 3,- but are only 84 f broad. They are borne on 



talks of several joints, the foot becoming no larger than the surround- 



ing epidermal cells in which 

 it is imbedded. All the walls 

 are only slightly thickened. 

 These hairs disappear soon 

 after fertilization, leaving scars 

 which are evident only on the 



immature fruit. 



Stomata (sto) are* very nu- 

 merous, occurring singly or 

 in groups. They have rather 



cells and thin- 



large guard 



A 



walled accompanying cells. 

 2. Hypoderm (hy).— 

 layer, many cells thick, con- 

 taining chlorophyll, forms the 

 green tissue of the rind. The 

 outer layer consists of short 

 cells, resembling those of the 



Fig. 24- 



Citrullus vulgaris 



Schrad. 

 with 



epicarp in size and shape; the Pericarp in cross-section; ^ u ^^ ocarp 



following layers are made Up «<>> sto ™, ; * * h f Tparenchvma between 



of cells smaller in size and ^pTolstott is;' -, middle mesocarp. 



^odiametric. Numerous pits xi6o. 

 ar e present, the walls appear- 

 ln g distinctly beaded in surface view. 

 °ccur throughout the tissue. 



Small intercellular spaces 



P 



In the very young 



fruit the cells are 



s 



mall 



aroups of cells 



and isodiametric, but after a few weeks single cells ^ ^^ ^ 

 Sicken their walls and become pierced with pits, 

 distributed about the fruit just within the hypoderm 

 of the fruit continues, these cells increase in numbe , 



As grow 



the groups 



