9°9l 



BARBER-FRUITS AND SEEDS OF CUCURBITACEAE 



275 



to the large ones of the middle mesocarp. They are isodiametric, have 

 thick walls and intercellular spaces, and but few contents. 



4. Middle mesocarp (fig. 4). — 

 In this layer the cells become 

 gradually larger, thicker-walled, 

 and more loosely arranged. They 

 contain small starch grains {am), 

 reaching a maximum size of 10 ^. 

 The outer cells contain a con- 

 Mderable number of these grains 

 but the increase in size of the cells 

 is accompanied by a decrease in 



This 



large- 



amount of starch. 



5. Inner mesocarp. 

 layer consists of rather 

 celled parenchyma with no evi- 

 dent contents. 



Bundles and isolated sieve 

 tubes, together with anastomos- 

 ing latex tubes (lat) are found 



Fig. 3 .-Cucurhita Pepo U Immature 



_w**r«* iuu\.o yiuij <xj.v* ivwuu. ji Uj, j. y^w~>~ * # . 



throughout the mesocarp, while epicarp in surface itoj. <*> ^ 



• , , with <«, jointed conical hair, i , l<m 



m the center of the fruit the™ - *""" 



ere hair, and sto, stoma. X 160. 



■ a great mass of tough fibers, 

 >unoun led by the remains of the broken-down parenchyiv^ 



£ TV.O M J near t) appea 



Fig. A—Cucurbita Pepo L, Cross- 



'on of mesocarp showing am, 



ar ^ h grains, and lat, latex tube. 

 X160, 



seeds as a thin membrane of tong^ 

 tudinallv elongated cells, arranged 

 end to end in rows. The mner wall 

 b about the same thicknc- as he 

 outer wall of the epiderm.s of h 

 spermoderm, to which it ,s qurte 

 , rmlv attached; from the dn-eds 



however, it may be readily separat I 

 as a. hin, transparent, colorie-^m. 



Spermoderm (figs 5. ">• 



l avcr s making up the sper- 



five 



moderm are as follows : 



