The Plantlet. 39 
this seed, unlike the pea, bean and pumpkin, the plantlet 
and seed-case do not make up the whole bulk of the seed. 
The remaining part shown at A, consists mainly of cells 
containing starch grains and oil drops, which serve as food 
for the plantlet during germination,—since active pro- 
toplasm cannot exist without nourishment (13). In the 
pea, bean, pumpkin and other seeds of this class, the food 
supply, instead of being stored by itself, as in the corn- 
grain, is contained within the plantlet or embryo,— mainly 
in the fleshy cotyledons. When the food supply of the seed 
is separate from the embryo, as in corn and many other 
seeds, it is called the endosperm. 
It is the food supply of the seeds that makes them so val- 
uable as food for animals. 
36. The Plumule (plu’-mule). If we look between the 
cotyledons of the bean plantlet, (Fig. 8), at the point of 
their union with the hypocotyl, we may see a pair of tiny 
leaves, and by carefully separating these, if need be, with 
the point of a pin, we may discover a minute projection,— 
the growing point (51) of the stem between them. These 
leaves, with the growing point, form the plumule,—the ter- 
minal bud of the plantlet. These tiny leaves become the 
first true leaves, and the growing point between them de- 
velops into the stem and later leaves. By close examination, 
we may make out the plumule in Figs. 7,9 and 10. In the 
pea and corn, it has already made considerable growth. 
57. Thus we see that the plantlet or seedling consists of 
three parts, viz., the hypocotyl, the cotvledons (in some 
plants cotyledon) or seed-leaves, and the plumule or termi- 
nal bud. 
