Buchanan County bulletin. [volume] (Independence, Iowa) 1869-1891, 1878-10-11
COlOrS in Leaves and Flowers.

All common leaves contain green
pigment, known to chemists as chloro-
phyl, from which they derive their ordi-
nary color The cells of the leaf are
stored with this pigment, while their
transparent walls give them the super
! fetal sheen which we notice so distinct
ly in the glossy foliage of the laurel and
the bright fronds of the hearts tongue
fern. But very slight chemical changes
in the composition of leaves suffice to
give them different color, which is not
surprising when we recollect that color
is nothing more than light, reflected in
greater or less proportions of its constit-
uent waves. The fashionable pelargo-
NUNS, coleuses and begonias, or the
dark sedums which are employed to
form the quaint carpet gardens so much
in vogue, show.us how easily the green
coloring matter can be replaced by va
rious shades of purple, red and brown.
These changes seem on the whole to be
connected with some deficient nutrition
of the foliage. 1t would appear that
the normal and healthy pigment is a rich
green; but that, as the leaf fades and
dies, it passes through successive stages
of orange, pink and russet. The autumn
tints of the forest, the crimson hues of
the Virginia creeper, and the transitory
colors of dying plant, all show us
these passing nuances. If single leaf,
or even particular spot upon leaf, is
instiiciently supplied with nutriment, its
first symtom Of i'll health is a tendency
to paleness or jaundiced yellowness. If
an insect turns some portion of it into a
gall-nut or blight, the tips assume a
beautiful pink hue. In short, any con-
stitutional weakness in the leaf brings
about changes in its contained pigments
which result in an altered mode of re-
fecting light. Or, to put the same fact
in another way, any change in the com
position of the pigments is apt to be ac-
companied by change in their color.
Now the ends of long branches are nat
urally the least nurtured portions of a
plant, and the young leaves formed at
such spots have a great tendency to as
sumo a brown or pinky hue. Fur lther-
more, these spots are exactly the places
where flowers are formed; flowers being,
as we saw above, mere collections of
aborted leaves, destined to fulfill the
functions of parents for future genera
tions at the point where the vigorous
growth of the original plant is beginning
to fail. Nothing can be more natural,
therefore, than that the flower leaves
should show an original tendency to ex-
hibit the brilliant hues; a tendency
which would of course be strengthened
by natural selection if it gave the plant
and its descendants any superiority over
others in the struggle for life. 1t should
be remembered, too, that the flower diff
fers from the leaf in the fact that it is
not self-supporting. The green portions
of plant are it's mouths and stomach;
they are perpetually engaged in assimi-
lating from the air and the water those
elements which are fitted for its growth
But the flower is a purely expensive
structure; it does not feed itself; it is
fed by other portions Of the plant 1t
uses up, in the act of growing and ex-
panding, energies derived from the food
which has been stored up by the chlor-
ophyl elsewhere. Accordingly, we
might expect it's pigment to present
that less energetic, more worn-out form
which produces the brighter hues of au-
tumn and the pink tips of growing
bough. From whatever point of view
we regard it, we see that a flower is
naturally supplied with some colorins
matter less active than that green sub
stance which forms the assimilativt
agency in common leaves. 1t is easy
therefore, to guess how certain plants
may have acquired the first tinge Of
color around their organs of fructifica
ton, and thus have attracted the eyes
Of insects by their superior brilliancy.-
. Coymh,W Magazine.