recollect that. The temperature and
moisture required for the germination of the seed is then employed in
producing the saccharine fermentation within it?

MRS. B.

Certainly. But, in order to understand the nature of germination, you
should be acquainted with the different parts of which the seed is
composed. The external covering or envelope contains, besides the germ
of the future plant, the substance which is to constitute its first
nourishment; this substance, which is called the _parenchyma_, consists
of fecula, mucilage, and oil, as we formerly observed.

The seed is generally divided into two compartments, called _lobes_, or
_cotyledons_, as is exemplified by this bean (PLATE XV. Fig. 1.)--the
dark-coloured kind of string which divides the lobes is called the
_radicle_, as it forms the root of the plant, and it is from a
contiguous substance, called _plumula_, which is enclosed within the
lobes, that the stem arises. The figure and size of the seed depend very
much upon the cotyledons; these vary in number in different seeds; some
have only one, as wheat, oats, barley, and all the grasses; some have
three, others six. But most seeds, as, for instance, all the varieties
of beans, have two cotyledons. When the seed is buried in the earth, at
any temperature above 40 degrees, it imbibes water, which softens and
swells the lobes; it then absorbs oxygen, which combines with some of
its carbon, and is returned in the form of carbonic acid. This loss of
carbon increases the comparative proportion of hydrogen and oxygen in
the seed, and excites the saccharine fermentation, by which the
parenchymatous matter is converted into a kind of sweet emulsion. In
this form it is carried into the radicle by vessels appropriated to that
purpose; and in the mean time, the fermentation having caused the seed
to burst, the cotyledons are rent asunder, the radicle strikes into the
ground and becomes the root of the plant, and hence the fermented liquid
is conveyed to the plumula, whose vessels have been previously distended
by the heat of the fermentation. The plumula being thus swelled, as it
were, by the emulsive fluid, raises itself and springs up to the surface
of the earth, bearing with it the cotyledons, which, as soon as they
come in contact with the air, spread themselves, and are transformed
into leaves. --If we go into the garden, we shall probably find some
seeds in the state which I have described--

[Illustration: Pl