ke that which
now exists in parts of the Southern States of this country. It seems
probable from the history of the past that the next revolution in our
northern hemisphere will dissipate the ice about the arctic pole, and
make a wide realm now uninhabitable to man fit for his use.

The foregoing little sketch of a few of the great events of the earth's
history does not take into account the greatest of them all, the coming
of man. But the conditions which surround the appearance of this flower
of the earth are as yet so imperfectly known that they cannot well be
considered.

HINTS TO YOUNG BOTANISTS.

BY CAROLINE A. CREEVY.

ROOTS.

When we are about to do a thing thoroughly and systematically we often
say we will "begin at the root of the matter." That is because the root
of a plant is supposed to be the first thing in its life. It is indeed
the foundation, the substructure of a plant, but not strictly the first
thing that starts to grow. The little stem feels the first quiver of
life, and the root follows. You can see the little stem, or _caulicle_
in fat seeds like squash and melon, beans and pease. Split a squash
seed, and between the two fat sides the caulicle lies cozily tucked,
like a tiny tail or handle. Plant a squash seed in the earth. The
caulicle, fed by the two fat sides, pushes its way upward into the air,
making a stem with leaves, and finally a big vine, while from its lower
end the root develops and pushes itself as fast as possible into the
earth.

The roots of some plants are small. I think most weeds make pretty large
and strong roots, which are hard to pull up. But when a tree has grown
to its full size its roots are almost as large as its branches. I once
saw a fine old maple-tree cut down, and its roots dug up to make room
for a cellar. I was surprised to see what a big hole the roots made. Two
men dug for several days before they had the roots all up.

The work for the roots to do is to drink water. The upper half of the
plant is very thirsty, and calls constantly for water. The roots push
and dig into the moist soil, drink in water, and pass it up by a sort of
pumping process. Only think, drinking and pumping! That is what roots
do. And so if the earth is dry, and the roots can find nothing to drink,
the plant will die. But after a shower see how glad the leaves seem, and
how stiff and straight they stand, because the roots are sucking up
great draughts of water.

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