Oxford Democrat. [volume] (Paris, Me.) 1833-1933, 1917-11-06

Why the Leaves hihge Their Color.
II requires no vivid Imagination TO
picture Mother Nature going about 10
the autumn days with . liberal supply
Of paint with which she colors tho leaves
Of the trees and other plants and thereby
produces tho vivid tinfs which character
Ike tho foliage OF this season. In reality
the change In coloring 10 the result Of
certain chemical processes which take
place In the leaves.
The change 10 not, % many people
suppose, due to the action Of frost, but
IL . preparation for winter. Ali during
the spring and summer the leaves have
served 20 factories, where the foods
necessary for the trees' growth have
been manufactured. This food making
takes place In numberless tiny cells Of
the leaf and 10 carried ON by small green
bodies which give the leaf its color.
These ohlorophyll bodies, a. they are
known, make the food OF the tree by
combining carbon taken from the car
bonlc acid gas Of the air with hydrogen,
oxygen, and various minerals supplied
by the water which the roots gather.
In the fall when the cool weather causes
slowing down of the vital processes,
the work of the leaves comes to an end.
The machinery of the leaf factory IL
dismantled, 80 to speak, the chlorophyll
is broken up into the various substances
Of which 1t Is composed, and whatever
food there is on hand 10 sent to the body
Of the tree to be stored up for use In the
spring. All that remains in the cell
cavities Of the leaf is watery substance
In which few oil globules and crystals,
and small number of yellow, strongly
retroactive bodies can be seen. These
give the leaves the yellow coloring 80
familiar In autumnal foliage.
1t often happens, however, that there
is more sugar In the leaf than can be
readily transferred back to the tree.
When this is the case the chemical com.
bination with the other substances pro-
duces many colored tints varying from
the brilliant red of the dogwood to the
more austere red.browns Of the oak. In
coniferous trees, which do not lose their
foliage In the fall, the green coloring
matter takes on q slightly brownish
tinge, which, however, gives way to the
lighter color In the spring.
While the color Of the leaf is changing,
other preparations are being made. At
the point where the stem Of the leaf Is
attached to the tree, special layer of
cells develops which gradually sever the
tissues which suppori the leaf. At the
same time Nature heals the cut, so that
when the leaf is finally blown off by the
wind or falls from Its own weight, the
place where 1t grew on the twig is
marked by scar.
Although the food which has been
prepared in the cell cavities lie sent back
to the tree, the mineral substances with
which the walls of the cells have become
impregnated during the simmer months
are retained. Accordingly, when the
leaves fall they contain relatively large
amounts of valuable elements, such as
nitrogren and phosphorus which were
originally part of the soil. The de-
composition of the leaves results in
enricbiDg the top layers of the soil by
returning these elements and by the
accumulation of humus. That is why
the mellow black earth from the forest
floor Is so fertile.