CHAPTER XIV 
THE SEED 
A Seep is a fertilized and matured ovule containing an 
embryo. 
The Empryo is a young plant in a dormant state of existence. 
It is capable of remaining alive for a long period under a broad 
range of conditions of temperature and moisture. When 
fully developed within the seed it consists of four principal 
parts: the caulicle or embryonic stem, the plumule or embryonic 
bud, the radicle or embryonic root and one, two or more seed 
leaves called cotyledons. 
The plumule is at the summit of the caulicle and consists of 
the young growing apex of the caulicle with delicate rudimentary 
leaves enveloping it. The radicle is a continuation of the lower 
end of the caulicle. It develops, upon the sprouting of the 
seed, the primary or first root of the seedling. The cotyledons 
frequently are carried above the soil, upon germination, and 
there function to build up food for the seedling plantlet until the 
latter has developed foliage leaves. In some seeds the cotyledons 
contain stored food which is used by the embryo as it develops 
into the seedling plantlet. 
All that portion of an Empryo PLANTLET above the cotyledons 
is termed the eficotyl and all that part below the cotyledons, the 
hypocotyl. 
The purpose of the seed is to insure the continuation and 
distribution of the species. It is therefore an organ of reproduc- 
tion. Like all other organs of the plant, seeds exhibit irritability, 
nutrition, respiration and growth. These, in the dry seed, are 
in the state of reduced activity. When properly stored, seeds 
may live for one year, as those of Aconite and Larkspur, or one to 
three years, as those of the Grass family, or two to five years, as 
those of the Rose and Mallow families, up to 20 years, as those of 
Tobacco or rarely 5 to 87 yearsas those of the Bean and Pea family. 
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