The Savannah morning news., 1904-10-04
WHEN THE TREES
GO TO SLEEP,


But to-day there's feeling Of snow
Margaret E. Sangster.
When the woods put on their autumn
dress of gold and crimson and the
brow of nature is bright with autumn
leaves" do the little folks ever wonder
why the plain green of summer
changes so suddenly to such beautiful
glowing colors? Perhaps the grown
ups VIII say. if they are asked, that
Jack Frost does it. But that is a great
mistake, as we snail see if we only
take the trouble to think a little. II
is in August. long before the frost
comes, that the red maple "crinsons
to coral reef" and it is in the years
when the frost comes late that the
leaves color most beautifully.
What, then, is the reason for the
blaze of colors that makes the autumn
woods so beautiful? We do not know
exactly. Even the wise people who
write scientific books do not quite un-
derstand it, but they do tell us a few
things which it is interesting to know.
The yellow color i'm the leaves they
explain this. way: The green color in
ali plants is produced by something
called chlorophyll, from two Greek
words meaning simply leaf green. -
The chlorophyll is made up of two
substances, one blush and one yellow,
and, as every little man or woman who
owns paint box knows these two COL
ors to~ether make green. Now, when
the tree is getting ready for its Win
ter sleep these two substances sepa-
rate, the blue disappears and the yell
low is left to give it's color to the leaf
The red color is not quite so easy to
explain, but it is produced by the
waste mineral matter which has been
collecting in the tree since last spring.
This is taken up by the roots in the
water, which it is their business to
supply to the tree, and is stored chief
ly in the leaves, where it is very much
in the way, but partly through the
whole tree. Now. before the leaves
fall the tree takes from the leaves
everything it wants to keep and gives
to them everything it wants to get
rid Of and the collection of all this
waste matter in the leaves has much
TO do with their coloring. For this
reason the color is most beautiful after
rainy summer, providing the fall is
of the right kind. In rainy weather
there is great deal of water for the
roots to take up. and the more water
taken into the tree the more mineral
matter is stored up to color the leaves
in the fall.
The only color that Jack Frost has
anything to do with is dark brown.
That is the color of death. When the
delicate cells of the leaves are frozen
they die and turn brown.
The falling of the leaves is another
thing for which Jack Frost is usually
held responsible, but with which he
has nothing, or. at least very little
to do. Trees shed their leaves in coun-
tries where it never freezes at all, and
in the North a great many fall before
ha at t. a.
tumn winds which make them fall,
though they help a little, like the
frost A wind strong enough to blow
the leaves off would take the twigs
too and very likely uproot the tree.
The leaves fall simply because the
tree cuts them off. ] has no use for
leaves in winter. 1t doesn't expect to
eat during the winter Sleep and there
fore does not need the food which the
leaves manufacture, and though it al
ways has to breathe it can breathe
through it's roots and bark, Just as
human beings can breathe through
their skins.
Besides being useless the leaves
would also be dangerous If left on dur
ing the winter, as they would catch
the snow and wind, and thus break
the twigs and branches. Sometimes
an early snow finds the trees unpre-
pared, and then they have a very
hard time indeed. The snow collects
on the. leaves and the weight breaks
off great branches as thick as ones
arm. This would happen every year
If the tree had not learned to take off
its summer clothes in good time.
The cutting-of' process begins when
summer is at it's hight. Away back
in the dog days the trees began to grow
some cork cells between the leaf stem
and the twig. This was to prevent
an open wound when the leaf should
fall for tree can be wounded, Just
like an animal. Then, above the cork
seal it grew layer of another kind
of cells. This is called the layer of
separation, or cutting off layer, and
can easily be seen on the blackberry,
where 1t forms yellowish green ring
on the purple leaf stalk.
There are three rows of cells in this
cutting off layer, and after a while
the middle one dissolves into mucilage
so that there is nothing left TO hold
the leaf to the twig except some woody
threads which pass through the cut
ting off layer and through the layer of
cork. Then the cells that are left be-
gin to swell, and push the leaf stem
away from the twig, until at last a
Oun of wind or a frosty night snaps
the threads and the leaf falls to the
ground. The reason frosty nights
help In this work is because they freeze
the water that collects i'm the cutting
off layer. OF course, the little folks
all know that when water freezes II
expands, so when the water freezes in
the cutting-off layer, the leaf stem lie
pushed harder than ever. After frosty
nights In the late fall, therefore, there
is apt 10 be a great fall of leaves. That
is why people say that the frost makes
them fall, but If the tree had not al
most cut them off already the frost
would not do it, and a great many fall
without any help from either frost or
wind
After the leaves fall some trees cover
up the ends of the broken threads with
gum, as can easily be seen on the
horse chestnut. Here the cork seals
that grow at the base Of the leaf stalks
are shaped something like horseshoes,
and the gum covered ends of the
broken threads look like the nails in
the horseshoe.