Indian chieftain. [volume] (Vinita, Indian Territory [Okla.]) 1882-1902, 1889-07-04


end and loose behind. attalns complete
growth. The opening of the mouth.
too, becomes enormously enlarged, ex-
lending far back at the sides o. the
head.
But while these transformations are
truly remarkable IL is well to keep in
mind that, after ali. they are not essen
TALLY different from those through
which other animals pass in their
bodily development Take, Tor exam
pie, bird. lhe changes which take
place within the egg during the early
period OF incubation are quite the same
In their general nature as those which
The frog passes through after It has
completed tho period Of incubation.
(The frog matches from its egg by the
heat OF the SUM. The chief difference
Is that in the bird these changes are
completed during the egg stage. the
animal leaving the egg with all its
class characters in perfection. But In
the frog, at the time tho young leaves
the egg II Is In the fish stage, that Is
TO say, II has the characteristics OF a
class at least two grades below It's own
proper class. And so II must GO on in
its development after having passed
the egg stage; and as these final stages
take place before our eyes they attract
our attention, aud are in dangor OF
leading us to suppose that the develop
mental history OF the frog is peculiar
and anomalous.
Tho frog affords an example OF those
animals which secure protection from
the attacks OF their enemies by MIN
licking the color OF their surroundings.
BY some physiological process. tho
nature OF which is not we'll understood,
they are able to vary the color OF the
pigment OF the skin in correspondence
to the color OF their surroundings
Thus. when they sit in the grass on
the bank OF a pool or stream, they
change their color to green. and thus
are less likely to be seen by birds and
snakes, which are their chief enemies.
The frogs differ from most animals
in possessing no distinct organs OF de-
Tense. But his powerful leaping mus
cles stand him in good stead as a
means of escape, both when on the
shore and when in the water, in the
latter case enabling him to swim with
great quickness.
The sense-organs OF the frog are
well developed and are quick in their
action. The external part OF the ear
Is very noticeable, appearing as a
round, dark space just behind the eyes
II corresponds TO the tympanum or
ear-drum OF higher animals There
are delicately formed olfactory cells in
the nasal cavities. indicating that the
sense OF smell is fairly acute. The
eyes are well formed and are provided
with lids. the lower one alone is freely
movable. II the eye be touched 1t is
drawn inward under the upper lid and
at the same time the lower lid asceuds
to close the eye.
The manner in which breathing is
effected in the frog is peculiar. Tne
lungs are simple sacks. similar to the
swim-bladders of fishes. except that
they are dived internally into minute
chambers or cells. They are not sus-
pended in a chest cavity, but hang
loosely in the general cavity Of the
body. Hence they can not be filed
with air by means Of movements Of the
sides OF the body, as Is the case with,
the higher vertebrated animals But
mechanism Of similar principle OF
operation is found in the floor OF the
mouth. This is capable OF being
lowered by the muscular action, thus
greatly enlarging the mouth cavity.
The vacuum thus formed is filed by
air passing in through the nostrils.
These passages are then closed, and
the floor OF the mouth raised, the air
thus being forced into the lungs The
action is therefore not dissimilar to
that Of a force-pump. The lungs
having been filed. expiration takes
place by the mere reaction OF their
elastic tissue, as in the higher animals
The skin appears TO be a necessary
accessory organ in breathing. At any
rate frog soon dies when kept in a
dry place, the explanation seeming TO
be that the pores of the skin are closed
so that the blood is not sufficiently
purified. In winter they breathe
through the skin alone. And 1t has
been shown that in summer, when
their vital processes are in the highest
state OF activity, they live for long
time, when confined to breathing by
the skin alone, the nostrils having
been stopped or the lungs themselves
removed An experiment is reported
in which frog lived FIVE weeks after
having thus been deprived OF its lungs.
The winter habits of the frog are
not dissimilar 10 those OF other rep
lillian animals. II burrows into the
mud at the bottom of the pool and re-
mains In a torpid condition until
spring. The vital processes appear to
be sustained during the time by nutri-
ment stored up in special internal
organ called the fat-body.
As is we'll known. the spring is the
season OF the greatest activity with
these animals The discordant croaks
OF the male frog are a Characteristic
sound Of the warm spring night In
some species, as subseryient 10 the
production Of voice, there are large
dilatations Of the skin at the sides of
the head in the male. These sacks
having been filed with air, II is forced !
out along two membranous folds which |
by their vibration produce voice. A
frog can often be made to croak by |
stroking its sides and thus the action |
OF these sacks may be demonstrated.
In respect 10 intelligence the frog |
can not be said TO be in any wise re-
markable. It's instincts are very few.
II makes no nest, and in fact appears
70 give no attention whatever 70 its
young; the whole office OF maternity |