, they will be found to be protected by a
tough skin or coat. Within this the contents of the seed are divided
into two bodies of equal size lying close to each other and called
seed leaves or cotyledons (Fig. 41-5). Between them near one end or
one side will be found a pair of very small white leaves and a little
round pointed projection. The part bearing the tiny leaves was
formerly, and is sometimes now, called the plumule, but is generally
called the epicotyl, because it grows above or upon the cotyledons.
The round pointed projection was formerly called the radicle, but is
now spoken of as the hypocotyl, because it grows below or under the
cotyledons.

Examine a dry kernel of corn and notice that on one side there is a
slight oval-shaped depression (Fig. 41-1). Now take a soaked kernel
and cut it in two pieces making the cut lengthwise from the top of the
kernel through the centre of the oval depression and examine the cut
surface. A more or less triangular-shaped body will be found on the
concave side of the kernel (see Figs. 41-2 and 41-3). This is the one
cotyledon of the corn. Besides this will be found quite a mass of
starchy material packed in the coverings of the kernel and in close
contact with one side of the cotyledon. This is sometimes called the
endosperm.

Within the cotyledon will be found a little growing shoot pointed
toward the top of the kernel. This is the epicotyl, and another
growing tip pointed toward the lower end of the kernel; this is the
hypocotyl or the part which penetrates the soil and forms roots.

Now examine the seeds that were planted in succession. Some will be
just starting a growing point down into the soil. Some of them have
probably come up and others are at intermediate stages.

How did the bean get up?

After sending down a root the hypocotyl began to develop into a strong
stem which crooked itself until it reached the surface of the soil and
then pulled the cotyledons or seed-leaves after it (Fig. 42). These
turn green and after a time shrink and fall off.

The pea cotyledons were left down in the soil, the epicotyl alone
pushing up to the surface. The corn pushed a slender growing point to
the surface leaving the cotyledon and endosperm behind in the soil but
still attached to the little plant (Fig. 43).

USE OF COTYLEDONS AND ENDOSPERM

=Experiment.=--Plant some beans in a pot or box of soil and as soon as
they come up cut the seed-leaves from some of them and