The Middlebury register and Addison County journal. [volume] (Middlebury, Vt.) 1883-1885, 1884-01-18
MIMICS AMONG ANIMALS.
BIRDS, FISHES AND INSECTS THAT
ARE ABLE TO CHANGE COLOR.
Moths that Can Disappear Under
Their Pursucr's Eycs-Somc WOn-
dcrEul limitations of Form.

New York san reporter who was about
to sit down in an olive-green plush
chair. An investigation of the seat
brought to light green snake of the
exact hue of the plush, coiled up and
fast asleep.
pull up another CHAIR said the
snake owner with a laugh.
The reporter picked his way across
the room stepping on horned toad
that was huddled close to some Turkish
figures on rug, only to find the back
of another chair occupied by bright
green lizard from South Carolina. \
third trial, however, was successful
NO" said the naturalist, who was
busy with microscope, they have
not moved the Geological Garden up
here, but | have quite as good dis
play, though on a smaller scale. The
difficulty you had in seeing the snake
and anolis, and the fact of your step
ping on the toad, are illustrations of
the success of my experiments.
IF you have ever thought particu-
larly on the NATTER" he continued,
pouring little carmine into a sea of
radiolarians, "you must have noticed
that in all nature there is a strong
tendency to adaptation to locality.
This is especially so in regard to color,
and often true as to form. The little
snake that you came near sitting on is
perfect mimic of the rich green grass
in which it is found, and you would
never suspect its presence if you did
not see it move | am confident that
it can adapt itself to darker or lighter
shades. This morning | had it on
light-green cushion, and in a few min
utes it adapted itself to 1t so that it
was almost invisible, and now you see
it has assumed an entirely different
hue"
us the change physiological Sc
cret?"
Not at all. We have well-defined
ideas concerning it, In the first place,
we know that many animals change
their color at a moments notice,
especially fishes and reptiles. Among
the former the stickleback, perch, SER
ranus and dolphin are the most re-
markable. In many this change is
evidently made at the option Of the fish.
This is also true Of the reptiles, and
now for the explanation. Here is a
microscOpical section of a frogs skin.
You see it consists of two distinct por-
tons, the epidermis and the cults. The
former is made up of cells, while the
latter contains nerves, fbers and cavi-
ties for cell clements. These cells are
filled with pigment or coloring matter,
and are known as chromatophoSeS and
to their contraction and expansion is
due the coloring of various animals,
for all, from man down, have them,
differing in color in different indi-
vlduaiS and in various parts of the
body. Different cOlors or degrees of
intensity seem to cause a contraction
or expansion of the cells. Thus, in the
Collins, the pigment cells, that are
yellow when distended, assume an
orange-colored hue when contracted,
and the orange or red cells when
shrunk become brown, or black, as the
case may be. Now, when a fish that
habltually lives on white bottom
passes on to black one the change is
conveyed by the eye to the brain, and
telegraphed, so to speak, to the pigment
cells by way of what are called the
sympathetic nerves, and the change is
produced.
Glow do we know this? By watch
ing blind fish pass from one colored
ground to another. In such a case
there is no change at all. The eye is
the medium, yet there is probably no
intelligent appreciation on the part of
the animal that the change has been
made The experiments with the
sympathetic nerves are very remark
able. By cutting one fish has been
shown spotted on one side and striped
on the other, and, in fact, the coloring
is at the will of the skilled anatomist.
The anolis, our common Southern
lizard, that seems to take the place of
the chameleon, is the most wonderful
in its power of changing color, adapt
ing itself to variety of hues.
But probably the most striking
mlmics are those that initiate other
objects and animals in form. Here"
he continued, taking out large steel
engraving, sis a fish allied to our
Lophius that was captured by the
Challenger on her famous trip. You
see, it is all covered with barbels of
t'N''4 'h"o NNpNtlg iCotlllblO SHAMEFUL,
both in shape and color, and when
clinging to the bottom it is perfectly
invisible so to speak. a number of
our fishes are equally protected. Here
is sea horse that has recently been
discovered in Australian waters. 1t
has prehensile tail, and clings like a
ring-tailed monkey to the seaweed,
and from its back and tail at intervals
these long, pinkish streamers float,
exact in their imitation of the sur
rounding weed. Other sea horses have
more delicate ornaments that look like
fine lace or streamers, and so escape
detection.
Among insects there are even more
striking examples, Here is a cater
pillar that | received from China.
The finder informs me that when
aroused it initiates small shrew, so