304 



BOTANICAL GAZETTE 



[\PRIL 



face of the seed, but in the subepidermal layer. A cross-section 

 best illustrates this characteristic feature. The cells are much 

 shorter than broad, except where they suddenly elongate, running 

 down into the grooves of the subepidermal layer to form palisade 

 cells about 54 p in height. In surface view the whole radial wall 

 is thickened, without the thickened rods so characteristic of other 

 seeds. 



Subep 



—This coat, which varies in thickness, 



as above described, always consists of numerous (ten to fifteen) 



Fig. 41. Echinocystis lobata T« 

 Fig. 42. "-■--• - 



43 



orr. & Gr. Endocarp in surface view. AJ^ 



Echinocystis lobata Torr. & Gr. Subepidermal layer in tangenta ^^ 

 Fig. 43. Echinocystis lobata Torr. & Gr. Parenchyma with rap e 

 race vie"' VQ ~ 



X300. 



lew. X80. 



mged- 

 cros^ 



layers of sclerenchymatized cells. They are very looseh 

 with large circular spaces surrounded by thickened walls. ^ 



section the tissue appears only as a confused mass of cells, u^ 

 tangential section (fig. 42) the contour of the walls is very 

 The seed owes its color to the dark contents of the outer ce J* 



3. Sclerenchyma 



I) 



In cross-section this 



single 



cell layer 



j. Kjwrcnvnymu {SU). — in CrOSS-SCLliun w» — a . j fl 



appears as a palisade tissue, the cells, while only 4°^ broa ^ ^ 

 radially elongated to 180 fi. The walls are extremely thick a 



