pairs of stipules without any leaves at all. The rings thus become
separated in Magnolia, while in the Beech the first internodes are not
developed, leaving a distinct band of rings, to mark the season's growth.
The Magnolia is therefore less desirable to begin upon. The branches are
swollen at the beginning of a new growth, and have a number of leaf-scars
crowded closely together. The leaf-scars are roundish, the lower line more
curved. They have many dots on them. From each leaf-scar runs an irregular
line around the stem. This has been left by the stipules.

The flower-scar is on the summit of the axis, and often apparently in the
axil of a branch, as in Horsechestnut. Sometimes the nearest axillary bud
is developed; sometimes there are two, when the branch forks. The axillary
buds seldom grow unless the terminal bud is interrupted. The tree
therefore has no fine spray.

LILAC _(Syringa vulgaris_).

Ask the scholars to write a description of their branches and to compare
them with Horsechestnut. These papers should be prepared before coming
into the class, as before.

The buds are four-sided. The scales and leaves are opposite, as in
Horsechestnut. The outer pair sometimes have buds in their axils. Remove
the scales one by one with a knife, or better, with a stout needle. The
scales gradually become thinner as we proceed, and pass into leaves, so
that we cannot tell where the scales end and leaves begin. After about six
pairs are removed, we come, in the larger buds, to leaves with axillary
flower-clusters. The leaves grow smaller and the flower-clusters
larger till we come to the centre, where the axis is terminated by a
flower-cluster. There is a great difference in the buds on different
bushes and on shoots of the same bush, some being large, green, and easy
to examine, others small, hard, and dark-colored. It is better, of course,
to select as soft and large buds as possible for examination.

[Illustration: FIG. 14.--Lilac. I. Branch in winter state: _a_, leaf-scar;
_b_, bud-scar (reduced). 2. Same, less reduced. 3. Branch, with leaf-buds
expanded. 4. Series in a single bud, showing the gradual transition from
scales to leaves.]

That the scales are modified leaves is plainly shown by the gradual
transition they undergo, and also by the fact that buds are developed in
their axils. If any of these can be shown to the pupils, remind them of
the experiment where the top of a seedling Pea was cut off and buds