OF GERMINATION. 95 
and become root. The plumule is the young bud destined 
to expand upwards and become stem and leaves. The cotyle- 
dons are two young leaves, thick and bulky, full of starchy 
matter to feed the embryo when it shall awake and begin to 
grow. 
192. In the Wheat-seed (Fig. 312) we find, besides the 
embryo, a white, mealy mass (a), well known when ground 
into flour. This mass is evidently intended to answer the 
same purpose as the starchy cotyledons of the Bean—to 
nourish the embryo. The radicle (), the plumule (p), the 
cotyledon (¢). and the albumen (@), are clearly shown. Fig. 
313 (seed of Four-o’clock) also shows albumen; here the em- 
bryo is coiled into a ring around the albumen. Thus we see 
that the food of the young plantlet is laid up somewhere in 
every seed, either in the bulky cotyledons of the embryo 
itself, or in the albumen outside the embryo. 
193. We have, then, seeds albuminous, and seeds exalbu- 
minous; seeds two-cotyledoned, and seeds one-cotyledoned. 
LESSON XXV. 
THE SEED BECOMING A PLANT. 
194. We have seen that the ripened seed is a miniature 
plant, living, but sleeping; packed and sealed up for trans- 
portation. It may continue to sleep, perhaps, for years, if 
191. Describe the nature and destiny of the radicle; of the plumule; of 
the cotyledons. 
192. Of what does the Wheat-seed consist? What is the intention of ihe 
albumen? the position of it in Wheat? in Four-o’clock? 
193. What seeds are albuminous? exalbuminous? What seeds are two 
cotyledoned? one-cotyledoned ? 
