which are remarkable for the bright shining,
pink, red, and silvery grey skins of their seeds :
moreover, cultivation has great influence upon
their colour.

It has been said, that there are seeds which
have no skins whatever. As yet the only I
seed known to have no covering is that of
the ivy-leaved Veronica, or Germander
Speedwell.

Between the skin and the young plant
there nearly always exists a yellowish, or
greenish, greyish or brownish substance,
which forms the future nutriment of the
plant. This substance is called the perisperme
or albumen. The word Perisperme
was introduced into France by Jussieu, and
Gratner introduced into England and
Germany the word Albumen, on account of the
supposed resemblance of this tissue to the
albumen or white of an egg. There are three
sorts of perispermes — the farinaceous, the
oily, and the horny. In seeds like corn and
rice, the perisperme is farinaceous; being
composed of very small grains of fecula, and
containing a small proportion of sugar, azote,
and oil. In seeds like the ricin and poppy
the perisperme is oily, containing no fecula,
but albuminous matter and oil in water.
In seeds like the coffee and the date, the
perisperme is horny, being composed of hard
cells, containing only a little sugar and
albumen.

In a few plants, like the Nenuphar or
Indian water-lily, there are two perispermes,
placed one above the other.

When the skin of a seed is torn off, the
peculiarities of the embryo are seen. If the
seed divides naturally into two parts or lobes,
the plant will have two primordial leaves;
and, if the seed remains whole, the plant will
have only one primordial leaf. The lobes of
the seed are called Cotyledons, all flowering
plants being classified according to the number
of their cotyledons; and four-fifths of the
vegetable kingdom having two cotyledons.
The plants having only one seed-lobe are
called Monocotyledons, and the plants having
two seed-lobes are called Dicotyledons. A
seed with one lobe looks as if one of its
cotyledons had been taken off, and, instead of
spreading out like a leaf, takes the form of a
sheath or a top.

There are plants which have more than
two cotyledons; the seeds of some pine trees
have twelve; and the flowerless plants have
none at all.

The embryo itself is between the seed-
lobes, and is the future plant in miniature.
Linnaeus called it the corculum or little
heart. It is almost always white in colour,
the only known exceptions to this rule being
the embryos of the Mistletoe, the Theobroma,
and the turpentine pistachia-nut tree. The
embryo is divided into two parts, one called
the germule or plumule, growing upwards
and becoming the stem and leaves; the other
called the radicle, growing downwards and
becoming the root. These different parts
are distinctly visible in the common bean.

In many seeds the cotyledons and
perisperme are very small, and the little heart is
very large; and in others the lobes and
perisperme are very large and the embryo
is very small. In the vegetable ivory, a seed
about the size of an orange which is as hard
and white as ivory, the embryo only occupies
a space about the size of a pea, all the rest
being taken up by the seed-lobes and
perisperme. When the embryo is very large
there often is no perisperme, and the little
heart contains the substances necessary for
its own nutriment. Sometimes the embryo
contains fecula as in the French bean, but it
is generally accompanied by another
substance called legumen, which forms little
hard granules, and is coloured blue by the
application of azote.

All the substances contained in the different
kinds of perisperme are to be found in
the embryos. In some embryos there is a
great quantity of vegetable albumen, and in
others there is a great deal of oily matter,
especially in such plants as the cruciferes or
cross-flower bearers, and the composees or
dahlias. The embryos containing large
quantities of oil, like the Colza, have generally
a very thin skin.

Three simultaneous conditions are necessary
for a plant to germinate; humidity,
heat, and oxygenised air.

Humidity is necessary because it swells
the grain and causes it to break through the
skin; sometimes, however, only just enough
to allow the embryo to come out. Water
brings different gases to the young plant,
which are necessary for its existence, and
especially oxygen. Water also dissolves the
substances contained in the cells and conveys
them to nourish the little plant.

Nature has arranged that plants growing
even in the burning desert shall be provided
with enough of water for the germination of
their seeds; and one of the most remarkable
instances of this fact is furnished by the
Anastatica Hierochuntica, or rose of Jericho,
which grows in the arid wastes of Egypt,
Palestine, and Barbary; upon the roofs of
houses and among rubbish in Syria; and in
the sandy deserts of Arabia. This little
plant, scarcely six inches high, after the
flowering season loses its leaves, and dries up
into the form of a ball. In this condition it
is uprooted by the winds, and is carried,
blown, or tossed across the desert into the
sea. When the little plant feels the contact
of the water, it unfolds itself, expands its
branches, and expels its seeds from their
seed-vessels. The seeds, after having become
thoroughly saturated with sea water, are
carried by the tide and laid upon the
seashore. From the seashore the seeds are
blown back again into the desert, where,
sprouting roots and leaves, they grow into
fruitful plants, which will in their turns, like