The suburban citizen., 1901-11-30
ARCTIC WHITE ANIMALS
PROCESS INVOLVES SUBSTITUTION
OF ONE COAT FOR ANOTHER,

No Control over the Change = A Puz-
cling Problem For the NaturalIsts.
1t has been generally assumed that
such animals as change the color Of
their coats in winter-chiedy varieties
in the Arctic regions-do so by a
bleaching process. Experiments made
fifty years ago on the Arctic lemming
"a mouse-likc creature) showed that its
hair could thus be turned white by
sudden lowering OF temperature, and
this was thought to be the normal pro-
cess. Actual observation, however,
leads to the belief so we are told by
the English naturalist, r. LydellIer,
in knowledge, that the method is quite
different and involves an entire substi-
tuition Of one coat for another. He
says:
1T is perfectly well known that
apart from those which turn white in
winter, a large number of animals
have winter coat differing markedly
in color, as well as IN length, from the
summer dress. The roebuck, for in
stance, is of a brilliant foxy red in
summer, while in winter 1t is gray
fawn with large patch Of pure white
on the buttocks. And 1t is quite clear
that the change from red to gray, and
the development of the white rump-
patch, is due to the shedding of the
short summer coat and it's replace
ment by the longer winter dress. OBJ
viously, therefore, il is natural to eX-
pect that n similar change of coat
takes place in the case Of mammals
which turn white in winter.
"That the change in spring from
white to dark dress is due to a she'd
ding Of the fur seems to be admitted
on all hands, for it would be obviously
quite impossible for long hairs to be-
come short, or for white ones to turn
brown. And even in animals which
do not alter their color in any very
marked degree according to season
the spring change Of coat is sufficiently
obvious. Moreover, in spite of
the natural tendency to believe in
blanchng on account Of the aforesaid
abnormal instances of turning white
in 4 single night, there is abundant
evidence to show that even in human
hair the change from dark to white
as age advances is brought about by
the replacement Of dark hairs by
white ones, and not by the bleaching
Of the former. In this case, however,
the change, instead Of being seasonal
and sudden, is gradual and due to age.
If the change was due to blanching we
81 nj II trte,
which were partially white and par
TALLY brown (or black, as the case
may be-.
"As a matter Of fact, however, those
of us who have reached an age when
! silver hairs have begun to make their
appearance among the brown can easily
satisfy themselves that such hairs are
white throughout their entire length,
and that hair half white and half
brown is quite unknown. From this
we infer that the change from brown
to white takes place in human beings
by the gradual shedding of the dark
hairs and their replacement by new
ones from which pigment is entirely
absent. So that normally there is no
such thing as bleaching of individual
hairs. The change is, indeed, precise
ly similar to that which takes place
at the approach of winter in NAM
mails that habitually turn white at
that season, with the exception that,
as a general rule, 1t is extremely slow
and gradual, instead Of being compar-
atively rapid, and also that the white
hairs differ from their dark predeces-
sors soley by the absence of coloring
matter. Unfortunately, there is no
subsequent replacement Of the white
hairs by dark ones"
Experiments in this country on the
American variable hare go to show
that the animal itself has no control
over the change, and observation in
England seems to demonstrate that 1t
is also quite independent Of tempera-
ture. The late DR.. Cones, however,
the eminent American naturalist,
stated that although the change Of
coat OF the Adirondack ermine takes
place regularly, its color is governed
by the temperature at the time Of the
change. DR.. @. II. Merriam asserts
that the white coat is assumed only
after the first snowfall, and this would
seem to be connected with the reason
for the change, which, it appears. Is
protective. Says the writer:
ut is, Of course, quite evident that
the assumption OF a white winter liv-
cry by mountain hares and ermlnes
living in regions where the snow lies
on the ground for a considerable por-
ton Of the year is for the purpose Of
rendering such animals as inconspicu-
GUS as possible when in their native
haunts. And, so far az we know, such
a change is universal among the spe-
cies named when dwelling in high
northern lattudes,"
In closing, Mr.. Lydekker states an
interesting fact regarding the blue
and white Arctic foxes whose fur Is
now so fashionable 1t has been sup
posed that the white fur was the win.
ter and the blue the summer coat Of
one and the same animal, but the wri-