496 
The Seed and its Germination. 
plants. Carbohydrates, such as starch and sugar, fats, and the 
peculiar nitrogen-containing material known as albuminoid, or 
preferably as proteid substance, which are the matters necessary 
for the nutrition of the animal body, are found to be equally 
essential for that of the embryo of the plant. Prepared and 
elaborated from simple inorganic materials by the parent, they 
have been stored away in certain of these cells before the off- 
spring separated from it. The most commonly occurring body 
met with here is starch (fig. 8). This is deposited in the form of 
definite grains, the shapes and sizes of which vary with the plant 
in which they are found (figs. 9, 10, 11). Many of them show 
Fig. 8.— Cells from Endosperm Fig. 9. Fig. 11. 
of WJieat. Starch Grains from (9) Potato, (10) Wheat, 
a, crowded with starch grains; b, HI) Maize. 
after removal of most of the latter. 
The protoplasmio network is now 
visible. 
a concentric striation, as if they were built up by the deposition 
of layer after layer upon a much smaller central mass. Chemi- 
cally these starch grains are composed of two substances, one, 
called granulose, being much more soluble than the other, 
which, from its resistant nature, is known as starch-cellulose. 
These two substances are intimately associated together in each 
layer of the starch grain, so that the granulose can be removed 
by appropriate solvents without interfering with the shape of 
the whole structure. 
Another body of the carbohydrate class is characteristic of 
some seeds, notably of the different varieties of palm. The cells 
contain no starch, but the whole seed is composed almost 
entirely of cellulose. The walls of the cells are enormously 
thickened, and their cavities are proportionately reduced in 
dimensions. They then contain only amorphous nitrogenous 
matter, with sometimes a certain amount of oil, as in the cocoa- 
nut palm. 
The albuminoid matter, or proteid, is often found in the 
