492 
The Seed and its Germination. 
development of cellular tissue in the interior of the cell in the 
ovule in which the embryo or young plant originated. This 
albumen must not be confounded with another substance known 
as albumin, which will be referred to later on. To avoid con- 
fusion it is best to speak of it as endosperm. When present in 
a seed it contains the reserve materials, and the embryo itself 
which is embedded in it is usually small, though its separate 
parts are as complete and as well recognisable as those of the 
larger embryo of the pea or bean. This form of seed is found 
Pig. 2.— Seed of Fig. 3.— Seed of 
Buckwheat in Beet in section, 
section. 
t, testa ; e, endosperm ; em, embryo, consisting 
of axis and two cotyledons ; c, the latter 
folded back. 
Fig. 4. Fig. 5. 
Seed of Castor-oil Plant dissected 
to show Embryo. 
(4) surface view of latter ; (5) section at 
right angles to (4) ; t, testa ; r, radicle ; 
p, plumule ; c, cotyledon ; e, endosperm. 
in the buckwheat, potato, carrot, parsnip, onion, beet, mangel, 
&c. (figs. 2, 3, 4, 5). 
According to the presence or absence of this endosperm or 
albumen, seeds are often spoken of as albuminous or exalbuminous. 
Thus, the seeds of buckwheat, potato, &c, are albuminous ; the 
leguminous and cruciferous seeds are exalbuminous. 
In the grasses and cereals, which are so important to us as a 
source of food supply, a still further modification of the albu- 
minous seed is met with (fig. G). Part of the embryo develops 
into a curious shield-like body, which is placed so as to separate 
the young plant from the endosperm. This body, which is 
known as the scutelluvi, is covered on the side facing fhe endo- 
sperm by a peculiar, delicate coat, which has a very important 
part to play in the processes of germination. Besides possessing 
this scutellum, the embryos in grasses and cereals differ from 
those hitherto mentioned in having only one cotyledon, or seed- 
leaf. 
This, then, is the state of things in the seed : a young 
plant resting and quiescent, but surrounded by, or filled witb, 
nutritive matters, and possessing the power of respondingto a 
suitable stimulus, usually that of moisture and warmth, by a 
resumption of active life and growth. 
The several parts mentioned can be very readily recognised 
