forming between them, while the internodes of these leaflets were making
quite a rapid growth. Subsequently, I found the leaflets also in the buds
themselves. I found these leaflets developed on the tree only in the
shoots containing flower-clusters, where they would be needed for the
future growth of the branches. I suppose the reason must be that the
flower-cluster does not use all the nourishment provided and that
therefore the axillary buds are able to develop. It would be interesting
to know what determines the stronger growth of the one which eventually
becomes the leader.]

There is one thing more the pupils may have noticed. The small round dots
all over the young stem, which become long rifts in the older parts, are
breaks in the epidermis, or skin of the stem, through which the inner
layers of bark protrude. They are called lenticels. They provide a passage
for gases in and out of the stem. In some trees, as the Birch, they are
very noticeable.

After discussing the subject thoroughly in the class-room, the pupils
should rewrite their papers, and finally answer the following questions,
as a species of review. I have thus spent three recitations on the
Horsechestnut. The work is all so new, and, if properly presented,
so interesting, that a good deal of time is required to exhaust its
possibilities of instruction. If the teacher finds his scholars wearying,
however, he can leave as many of the details as he pleases to be treated
in connection with other branches.


QUESTIONS ON THE HORSECHESTNUT.

How many scales are there in the buds you have examined?