Dicotyledons have bark, wood, and pith, and grow by producing a new ring
of wood outside the old. They also increase by the growth of the woody
bundles of the leaves, which mingle with those of the stem.[1] Twist off
the leaf-stalk of any leaf, and trace the bundles into the stem.

[Footnote 1: See note, p. 127, Physiological Botany.]

Monocotyledons have no layer which has the power of producing new wood,
and their growth takes place entirely from the intercalation of new
bundles, which originate at the bases of the leaves. The lower part of a
stem of a Palm, for instance, does not increase in size after it has lost
its crown of leaves. This is carried up gradually. The upper part of the
stem is a cone, having fronds, and below this cone the stem does not
increase in diameter. The word _endogenous_, inside-growing, is not,
therefore, a correct one to describe the growth of most monocotyledons,
for the growth takes place where the leaves originate, near the exterior
of the stem.

_Gray's First Lessons_. Sect. VI. Sect, XVI, §1, 401-13. §3. §6, 465-74.

_How Plants Grow_. Chap. 1, 82, 90-118.




VI.

LEAVES.