276 



BOTANICAL GAZETTE 



[apwl 



1. Epidermis (ep). — The prismatic cells form a continuous layer 

 without intercellular spaces. They are radially elongated, on the 

 flat side of the seed to 270 fi, on the edge to 50 /*, while the border con- 

 sists of a ridge of cells several times as high as those of the flattened 

 surface. The outer wall is thickened, but has no cuticle, and the radial 

 walls are very thin, with peculiar branching thickenings of cellulose. 

 The thickenings run from the base of the cell, one on each wall, as 

 single straight rods until near the outer wall, where they branch pro- 



I*ig. 5.~Cucurbita Pepo L. Seed elements in surface view; ep, ribbed palisa e 

 cells of epidermis; ep*, isolated rib; hy, subepidermal layer; set, sclerenchynia; *, 

 Pitted parenchyma; «a, reticulated spongy parenchyma; p*, parenchyma; f», sponff 

 Parenchyma; pa, inner epidermis of spermoderm; N, perisperm; E, endosperm- 

 X 160. 



fusely, giving rise to a beaded appearance in tangential section. After 

 maceration, or in scrapings of the spermoderm, the rods fall upon 

 their sides. nrpcp*»t,*«„ +1. 1 :- *„ c ?w. Indn 



— «, yicscnung ine appearance shown in j> 

 seeds the walls of this layer are frequently broken 



few of thp tfc,VU„».:_ _ . ,., 



fig- 5, e P 



may 



for the cut 



surface of the walls themselveZ 



Round starch grains (am) , up to 7 /x in diameter, of the type aire**} 

 described, occur in considerable numbers in the epidermal cells- 



" **-"— ' " ■ .Below the epidermis is a layer 



pid 



