The Norfolk Virginian. [volume] (Norfolk, Va.) 186?-189?, 1897-10-27
LEAVES IN OCTOBER
A Scientific Reason For Their Beautiful
HueS in Autumn.
JACK FROST HAS VERY LITTLE SHOW
Professor MacDpugni Describes the
Processes Which Pain. the wood.
ma Forests La such Fnrie~atcd
tolorS in October. hnrnctcr Of
SOIL Has Much Ia DO with Coiors.

Professor u. It. Macdougal writes an
interesting and Timely paper in the
October Harper about autumn |
Leaves" III which he explains scientiii- |
cally the brilliant changes of color
which they show ana the Junction which |
this plays in the economy Of plant life !
as TO why autumn leaves arc c0lorcd |
he says:
THE casting OF the leaf IS not a sud
den and quick response 10 any single
change in cnvironmeutal conditions,
but is brought about with 4 complex
interplay OF processes begun days or
perhaps weeks before any external
changes are to be seen. The leaf is
rich i'll two classes of substances one of
which is of no further benefit to il and
another which it has constructed at
great expense of energy and which is
IN Il form of the highest possible use
ruinesS TO the plant. 10 this class be-
long the compounds in the protoplasrn,
the green color bodies and whatever
surplus food may not have been pre-
NiouSly conveyed away. The substan-
Cos which the plant must needs discard
are i'll the form Of nearly insolublc
crystals and by remaining in position
III the leaf. drop with ii 10 the ground
ana pass into that great complex luno-
raiory OF the soil where by s!o.y meth
obs of diSintcgration useful elements
are set free and once again may bc
taken up by the tree ana travel their
devious course through roof hairs alon.
the SjuouS roots ana up through mil
hon ceiled columns OF the trunk. ont
through the twigs 10 The leaves once
more
Inc plastic substance within the leaf,
when would Inc loss To the pflnt if
thrown away, undergo quite a different
series of changes. These substances are
III me EXTREMIST parts OF the leaf. and
10 pass into the riaw; body must pcnr-
tratc many hundreds OF mcinb,lntS lv
d@fuS!on into the long cCnauc;ing cells
around the ribs or nerves and then down
INTO tie twiGS and stems The sucrrsa
iu' retreat OF this great mass of yaIua-
~" matter is not Il simple nrnhlam
These substances contain ri,ro,,an nc !,
part OF their ccmroucIds, and ms a con
sequence are very readily broken down
When exposed to tile sunlight In the
iiNinE normal leaf the green color forms
a moSi rifcctual Shield from the action
III me sun. but when fie retreat is he
gun. Que of the first steps results in The
iSint"graticn OF the ch.orophyu This
would allow the fierce RAYS of the Son
'rhS9er san 10 strike directly through
me broad cHranScs OF the leaf destroy
ing all within were not other mems
provided for protection. In The FIRST
liace, when the chlornphyu breaks down
among the resulting substances formed
Is cNan0nhYll thlUc) which ahsorbs In,
sun S rays !cl the same general manner
aS The ch!orGphyll. IN addition. ,ba
outer layers Of cells Of The leaf contain
DINER pigments some Of which have
been masked By the ci!loro,,hvlI. ana
others which arc formed as docnmp0si-
ton products, SO that the leaf exhibits
out Fardiy gorgeous Tunnply of coIors
IN reds, yeNows a5,d bronzcs that make
up the auiumnai display. From the
Wild riot of tntS shown hy n cIilmn nf
trees or shrubs, the rrrS rlrous innrnq-
sion might be gained that the colors are
accidental in their occurrence. This Is
iif from tho case. however. The KEY
note Of color in any species is constant
with minor and @caI variations. Tie
nirchcs are . golden yellow: oaks vary
through yellow orange - reddish brown:
the rcd maple becomes a rcd dark rel.
the tulip tree q light yellow: nayvthn,r,
and poison oak becomes violet: Whit.
he s,macs and vines take on Il iami Az
scarlet. These cbllrs c.SiIiili. some y,5i,
ton in accord with the character OF ~.
soil on which the plants stand
TN" plant is n most dclicalelv self
regulating organism. IT cannot IN
crease ihc water supply, but it may ana
| does decrease The cvar3ratirg surface
! by casting or shedding The leaves, p
reaction which it exhibits 20 othrr ,.,,
| ditions as well. Like the true seaman
| however the rlant does not shortrn
| sail by cutting away its canvas, but ,b,
| a deliberate and well timed series Of
! processes. wiihdrawa all Of tic substan.
ccS from the leaf which may lie useful
! To 1t back into Ms body before II dis
| cards the empty Sheets of cells; ;ud
| woody fibre of the pctiolc aud lamina
| Before proceeding; 10 n descrintjon nf
| the mechanism Of leaf fan il NAV ~.
| well to call attention 10 the poplIlar
and erroneous idea ;hnt the coIorin.r
/ and casting of autunnal leaves are due
| t" the action Of frost. 1t Isl true than
! The phcnGmcna Of nutunnal loaf far
are due 10 low temperature. hit as may
! lie seen from the above, the dccoliailou
of the plant is not 4 reaction 10 the
cold, but is an adjustment TO tho limited
water supply furnished by The chillad
roots. The reduction OF the water sun
ply and The beginning Of the processes,
! leading 10 the dc!oiiutiOn occur n Ion.
Zine haf2rc the temperature Of tho air
IS depressed TO the freezing point or