The Guthrie daily leader. [volume] (Guthrie, Okla.) 1893-1996, 1904-08-20
colon CHANGE N ANIMALS.
Theories Concerning the whitening
In Winter.

/ 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 Its origin they leave
as an unsolved problem.
find. however. that the change has
a deep physiological siRnihcanc
There is. for Instance, in manuals
definite sequence IN which the various
parts OF the body whlten. The Sc
quence corresponds to the summer &C
cumulations Of fat in the panniculus
adiposus. Thus the belly where per
/ ipherRl fat Is thickest, is permanently
white. and the rump, where also fat
accumulates thickly, is usually the
first part to whiten. Many Northern
mammals and birds, not usually re-
garded as of the winter whitening cat
ogory, are lighter in winter than in
summer. The whiteness OF whiCe
patches assumed in the former season
/ correspond 10 the fat tracts, so that
these species may be regarded as tub
, ject to the same process. In the
northern summer most animals ac-
cumulate fat always in a definite
manner as regards the regions where
/ 1t is deposited This fat is indicative
Of deficient oxidization and OF slug
gish metabollsm, and the process of
its accumulation is. therefore, oAs Il
atrophy. The fat accumulation and
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 Metchinon) is then removed, al
ways. however. commencing with
those parts where peripheral fat is
thicl,ssi, and atrophy therefore,
greatest Should there be a change Of
coat at this time the new hairs are in
fiuenced by the same conditions. In
very cold countries they come up whire
all over the animal; in more temper
a.e regions the parts only where fat
is thickest are white.
Although a pigmented hair can thus
undergo atrophy and loss Of pigment.
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 are
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-
ed 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
ly. 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 representative
of a family in which the back is us
ually whittier than the belly, ! hnd a
oorrespondingly 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 zygomatic arch) which
thus seem to produce an atrophy sim
liar TO that caused by underlying fat.
In many animals the hair atrophy as
sumes the form not Of whitening, but
Of badness. Marine mammals are
hairless in proportion to the develop
ment OF their perlpheral fat layers, fat
tening cattle lose their hair, while the
badness OF man corresponds In POSI-
ton to the blaze Of horses, and the
bare buttocks of monkeys to the white
rumps Of other animals.
Yellow and red frequently follow
the same rule Of distribution as white.
They are well known to be fat pig
ments