m 
SEED. 
The kernel is usually composed of the albumen, cotyledon, ami 
em.hryo. 
The Avoumen is that part of the kernel which invests the cotyle- 
dons or iooes, and is thought to afford the same support to the germ- 
inating emoryo, that the white of an egg does to a chicken. Both 
in respect to hardness and colour, the albumen, in many seeds, greatly 
resembles the white of a boiled egg. It is not considered an essen- 
tial part of the seed, because it is sometimes wanting ; but when 
present, it supports and defends the embryo while imprisoned in the 
seed, and serves for nutriment when it begins to germinate. It has 
no connexion with the embryo, and is always so distinct as to be 
easily detached from it. Albumen makes up the chief part of some 
seeds, as the grasses, corn, &c, ; in the nutmeg, which has very 
small cotyledons, it is remarkable for its variegated appearance and 
aromatic quality. It chiefly abounds in plants which are furnished 
with but one cotyledon. 
Fig. 110. I^ig"- 110 represents the cotyledons of the bean, 
as divested of the husk ; a, represents the cotyle- 
dons ; b and c, the embryo ; d, shows the petioles 
or stems of the cotyledons. 
Cotyledons, (from a Greek w^ord, kofule, a cavi- 
ty,) are the thick, fleshy lobes of seeds, which 
contain the embryo. In beans they grow out of 
the ground in the form of two large leaves. They 
are the first visible leaves in all seeds, often fleshy 
and spongy,, of a succulent and nourishing sub- 
stance, which serves for the food of the embryo at 
the moment of its germinating. Nature seems to 
have provided the cotyledons to nourish the plant 
in its tender infancy. After seeing their young charge sufficiently 
vigorous to sustain life without their assistance, the cotyledons in 
most plants wither and die. Their number varies in different plants, 
and there are some plants wiiich have none. 
Acotyledons, are those plants which have no cotyledons in their 
seeds; such as the cryptogamous plants, mosses, 
Mono-G-Ayledons, are such as have but one cotyledon or lobe in the 
seed ; as the grasses, the liliaceous plants, &c. 
Di-cotyledons, are such plants as have two cotyledons ; they in- 
clude the greatest proportion of vegetables ; as the leguminous, the 
syngenesious, &c. 
Poly-cotvledons, are those plants the seeds of which have more 
than two lobes ; the number of these is small ; the hemlock and the 
pine are examples. 
The number of cotyledons seldom varies in the same family of 
plants ; it nas therefore been assumed by some botanists as the basis 
of classification; but there are difficulties attending a method wholly 
dependant on these organs. In order to be certain as to their num- 
ber, it is necessary to examine the seed in a germinating state ; this 
is often difficult. The natural method of Jussieu is in part founded 
upon the number of cotyledons. 
The Embryo is the most important part of the seed ; all other parts 
seem but subservient to this, which is the point from whence the life 
and organization of the future plant originate. In most dieotyledo- 
Albumen— Describe Fig. 110— Cotyledons— What plants are called Acotyledons? 
—What Monocotyledons']— What Dicotyledons?— Polycotyledons 7— Why iS the 
number of cctyledons made the basis of classification— Embryo. 
