SEEDS 291 
The middle layers. The cells forming the middle layers 
(Fig. 4) have thin, wavy, light-colored walls which are frequently 
compressed, and it is with much difficulty that their outlines 
are made out. 
The inner epidermis. The cells forming the inner epidermis 
are rectangular in form, and they contain reddish-brown cell 
contents (Plate 123, Fig. 5). 
ENDOSPERM 
The endosperm. The cells forming the endosperm are large, 
rectangular in outline, usually one layer thick, and they contain 
aleurone grains. 
EMBRYO 
The embryo. The cells forming the outer layer of the em- 
bryo are smaller than the inner layers. and they are immediately 
inward from the layer of endosperm cells (Plate 123, Fig. 7). 
The cells forming the greater part of the embryo are large, 
rounded, and they contain aleurone grains and fixed oil (Plate 
123, Fig. 8). 
In white and black mustard are characteristic mucilage and 
palisade cells. 
In nux vomica, stropanthus, and St. Ignatius’s bean are 
characteristic hairs. 
In physostigma and kola are characteristic starch grains. 
In henbane, capsicum, stramonium, lobelia, and belladonna 
seeds are characteristic epidermal cells. 
In areca nut, colchicum, saw palmetto, and nux vomica are 
characteristic thick-walled, reserve cellulose cells. 
In cardamon seed are aggregate starch masses with irregular 
outlines. 
In bitter and sweet almond, linseed, pepo, and stropanthus 
are aleurone grains. 
In bitter and sweet almonds are stone cells. 
In linseed, quince seed, and in white and black mustard are 
epidermal cells with mucilaginous walls and contents, etc. 
