The Guthrie daily leader. [volume] (Guthrie, Okla.) 1893-1996, 1904-09-06
COLOR CHANGE IN ANIMALS.
Theories Concerning the Whitening
In Winter.

tncoFies concerning me Wnitcntnq
In Winter.
The winter whitening of animals,
though Of intense interest TO zoologists
is yer imperfectly understood. Most
writer's are satisfied to believe that
this change of color was perfected
somehow under the natural selection
for protective purposes Of adaptation
to environments. It's origin they leave
as an unsolved problem.
I find, however. that the change hs
. deep physiological sisnihcanc
There ia, for instance, in mamals
definite sequence in which the variou.
parts of the body whitsn. The sc
Quence corresponds to the summer ac
oumulations of fat in the psnniculus
adiposus. Thus the belly. where per.
iphsral fat is thickest, is permanently
white, and the rump, where also fat
aceumulatss thickly, is usually the
first part TO whiten. Many Northern
mammals and birds, not usually re-
garded as Of the winter whitening cat.
sgory, are lighter In winter than in
summer. The Wilderness or white
patches assumed in the former season
correspond to the fat tracts, so that
these species may be regarded az sub
ject to the same process. In the
northern summer most animals ac.
cumulatO fat. always in definite
manner as regards the regions where
It Is deposited This fat is indicative
of deficient oxidization and of slug.
gish metabollsm, and the process OF
its accumulation is, therefore. one Cf
atrophy. The fat accumulation ana
Atrophy are most marked in autumn,
at which season metabolism Is there
fore lowest. With the onset Of winter
cold the atrophy mAy extend to the
hairs. Their pigment (as observed
by Metchinoff) is then removed, al.
ways. however. commencing with
those parts where peripheral fat is
thickest. and atrophy therefore,
greatest. Should there be change OF
coat at this time the new hairs are in.
fiuenced by the same conditions. In
very cold countries they come up white
all over the animal; in more temper.
ate regions the parts only where fat
is thlckest are white.
Although a plgmented hair can thus
undergo atrophy and loss Of pigmenl,
l know OF no place where the color
is replaced. Animals once whitened
remain so until the spring molt. These
facts apply broadly to birds and NAM
mails, but the hare and the stoat ara
the species which have studied es-
pecially Similar laws cover a great
deal Of the distribution Of the white
color throughout the vertebrae ply
lum, wherein the connection between
white color and the peripheral fat
tracts (thus indicating local atrophy)
may be widely traced Thus domestic
animals, nearly all OF which are priz-
81 most for -their power Of accumulat.
ing fat, exhibit a strong tendency TO
the development OF white patches. In
both these and In wild animals the bel
iy, where occurs the principal fat
tract, is the most frequently white
part; next follow the rump and parts
of the neck, Of the limbs and Of the
head
Marked exceptions are no doubt
frequently due TO unusual arrange
ments of the panniculus adiposus.
Thus in the badger. a repres sentative
OF family in which the back is u.s.
ually whlter than the belly, and a
oorTespondingly exceptional arrange
ment Of the fat traces The white OF
the head-the "blaze" Of horses. the
facial stripes OF the badger-often af-
fects regions not Of fat accumulation,
but where the skin Immediately over.
lies bone and membrane (frontals and
nasAls and Eygomatic archl which
thus seem 20 produce an atrophy sim
liar 70 that caused By underlying tat.
I'm many animals the hair atrophy AZ