ned into a long thread, the chink
from which the plumule in time emerges is seen at the base, or near it,
so the caulicle is extremely short, and does not elongate, but sends out
from its base a simple root, and afterwards others in a cluster. Not
only does the cotyledon lengthen enormously in the seedling, but (unlike
that of Iris, Indian Corn, and all the cereal grains) it raises the
comparatively light seed into the air, the tip still remaining in the
seed and feeding upon the albumen. When this food is exhausted and the
seedling is well established in the soil, the upper end decays and the
emptied husk of the seed falls away.

43. In Maize or Indian Corn (Fig. 66-70), the embryo is more developed
in the seed, and its parts can be made out. It lies against the starchy
albumen, but is not enclosed therein. The larger part of it is the
cotyledon, thickish, its edges involute, and its back in contact with
the albumen; partly enclosed by it is the well-developed plumule or bud
which is to grow. For the cotyledon remains in the seed to fulfil its
office of imbibing nourishment from the softened albumen, which it
conveys to the growing sprout; the part of this sprout which is visible
is the first leaf of the plumule rolled up into a sheath and enclosing
the rudiments of the succeeding leaves, at the base enclosing even the
minute caulicle. In germination the first leaf of the plumule develops
only as a sort of sheath, protecting the tender parts within; the second
and the third form the first foliage. The caulicle never lengthens: the
first root, which is formed at its lower end, or from any part of it,
has to break through the enclosing sheath; and succeeding roots soon
spring from all or any of the nodes of the plumule.

44. =Simple-stemmed Plants= are thus built up, by the continuous
production of one leaf-bearing portion of stem from the summit of the
preceding one, beginning with the initial stem (or caulicle) in the
embryo. Some Dicotyls and many Monocotyls develop only in this single
line of growth (as to parts above ground) until the flowering state is
approached. For some examples, see Cycas (Fig. 71, front, at the left);
a tall Yucca or Spanish Bayonet, and two Cocoa-nut Palms behind; at the
right, a group of Sugar-canes, and a Banana behind.

[Illustration: Fig. 71. Simple-stemmed vegetation.]

Section IV. GROWTH FROM BUDS: BRANCHING.

45. Most plants increase the amount of their vegetation by branch