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. 1) are greatly e.ongated, 
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. 1) 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. 
