118 HISTOLOGY OF MEDICINAL PLANTS 



The outer wall of the layer of cells is thinner than the inner 

 wall. The innermost layer of cell is more uniformly thickened. 



The endodermal cells of aletris (Plate 35, Fig. 4) are yellow- 

 ish brown, slightly porous and striated. There are one or two 

 layers of these cells, and two of the smaller cells usually occupy 

 a space similar to that occupied by the radically elongated 

 single cell. 



On longitudinal view the endodermal cells of sarsaparilla 

 triticum, convallaria, and aletris appear as follows: 



Those of sarsaparilla (Plate 36, Fig. i) are greatly elongated, 

 the ends of the cells are blunt or slightly pointed, and the walls 

 appear porous and striated. 



Those of triticum (Plate 36, Fig. 2) are elongated, the walls 

 are porous and striated, and the outer wall is much thinner 

 than the inner wall. The end wall between two cells frequently 

 appears common to the two cells. 



Those of convallaria (Plate 36, Fig. 3) are elongated, and 

 the end wall is usually blunt. The outer wall is thinner than 

 the inner wall. 



Those of aletris (Plate 36, Fig. 4) are fibre-like in appear- 

 ance; the ends of the cells are pointed and the wall is strongly 

 porous. The longitudinal view of these cells is shown in plate 36. 



HYPODERMAL CELLS 



Hypodermal cells occur in sarsaparilla root and in triticum. 

 In the cross-section of sarsaparilla root (Plate 37, Fig. i) the 

 hypodermal cells are yellowish or yellowish brown. The outer 

 wall is thicker than the inner wall, the cell cavity is mostly 

 rounded, and contains air. The walls are porous and finely 

 striated. On longitudinal view the hypodermal cells of sarsa- 

 parilla (Plate 37, Fig. 2) are greatly elongated; the outer and 

 side walls are thicker than the inner walls. The ends of the 

 cells are blunt and distinct from each other. 



In cross- section the hypodermal cells of triticum (Plate 37* 

 Fig. 3) are nearly rounded in outline, and the walls are of nearly 

 uniform thickness. In longitudinal view (Plate 37, Fig. 4) 

 the same cells appear parenchyma-like, and the walls between 

 any two cells appear common to the two cells. 



