long misunderstood. Dr. J. Gray was shown at the Liverpool Museum some
living King Crabs, and the use they made of the tail-like appendages.
When turned over on their backs, he saw them bend down the tail until
they could reach some point of resistance, and then employ it to
elevate the body, and regain their normal position. Dr. Gray states
that they never have been seen to use this tail for the purpose which
has been often assigned to it--that is, for leaping from place to place
by bending it under the body, like the toy called a "spring-jack," or
"leaping frog."
[22] American Journal of Science and Art.
[23] W. C. Linnæus Martin, F.L.S.
MUSICAL LIZARDS.
A small Lizard, lately brought home from the Isle of Formosa by Mr.
Swinhoe, is decided to be a new species by Dr. Günther, of the British
Museum. Mr. Swinhoe found the eggs of this Gecko, or Lizard, in holes of
walls or among mortar rubbish. They are round, and usually lie several
together, resembling eggs of ordinary Lizards. The young, when first
hatched, keep much under stones in dark cellars, where they remain
until they attain about two-thirds of the adult size, when they begin
to appear in public to catch insects, but evincing great shyness of
their seniors. Mr. Swinhoe states that on the plaster-washed sides of
his bedroom, close to the angle of the roof, every evening when the lamp
was placed on the table below, four little Musical Lizards used to make
their appearance and watch patiently for insects attracted by the light.
A sphinx or a beetle buzzing into the room would put them into great
excitement, and they would run with celerity from one part of the wall
to the other after the deluded insect as it fluttered in vain, buffeting
its head, up and down the wall. Two or three would run after the same
insect, but as soon as one had succeeded in securing it, the rest would
prudently draw aloof. In running over the perpendicular face of the wall
they keep so close, and their movements are made so quickly, with one
leg in advance of the other, that they have the appearance at a distance
of gliding rather than running. The tail is somewhat writhed as the body
is jerked along, and much so when the animal is alarmed and doing its
utmost to escape; but its progress even then is in short runs, stopping
at intervals and raising its head to look about. If a fly perch on the
wall it cautiously approaches to within a short distance, then suddenly
darts forwards, and with its quickly-protruded, glutinous tongue, fixes
it. Apart from watching its curious manoeuvres after its insect-food,
the attention of the most listless would be attracted by the singular
series of loud notes these creatures utter at all hours of the day and
night, more especially during cloudy and rainy weather. These notes
resemble the syllables "chuck-chuck," several times repeated; and, from
their more frequent occurrence during July and August, they are thought
to be the call notes of the male to the female.
During the greater part of the day, the little creature lies quiescent
in some cranny among the beams of the roof or in the wall of the house,
where, however, it is ever watchful for the incautious fly that
approaches its den, upon whom it darts forth with but little notice. But
it is by no means confined to the habitations of men. Every old wall,
and almost every tree, possesses a tenant or two of this species. It is
excessively lively, and even when found quietly ensconced in a hole,
generally manages to escape--its glittering little eyes (black, with
yellow ochre iris) appearing to know no sleep; and an attempt to capture
the runaway seldom results in more than the seizure of an animated tail,
wrenched off with a jerk by the little fellow as it slips away, without
loss of blood. The younger individuals are much darker than the larger
and older animals, which are sometimes almost albinoes. In ordinary
fly-catching habits, as they stick to the sides of a lamp, there is much
similarity between this gecko and the little papehoo, or wall-lizard
of China; but this is decidedly a larger and much more active animal,
and often engages in a struggle with insects of very large size. The
Chinese colonists of Formosa greatly respect the geckos, in consequence
of a legend which attributes to them the honour of having once poisoned
the supplies of an invading rebellious army, which was thereby totally
cut to pieces. The geckos were raised to the rank of generals by the
grateful Emperor of China; which honour, the legend states, they greatly
appreciated, and henceforth devoted their energies to the extermination
of mosquitoes and other injurious insects.
CHAMELEONS, AND THEIR CHANGES.
"Nil fuit unquam
Sic impar sibi."--_Horat._
"Sure such a various creature ne'er was seen."
_Francis, in imit._
The Chameleon tribe is a well-defined family of lizard-like reptiles,
whose characters may be summed up as existing in the form of their feet;
the toes, which are joined together or bound up together in two packets
or bundles, opposed to each other; in their shagreen-like skin; in their
prehensile tail; and in their extensile and retractile vermiform tongue.
That the Chameleon was known to the ancients there is no doubt. Its
name we derive directly from the _Chamelæo_ of the Latins. Aristotle's
history of the animal proves the acute observation of that great
zoologist--the absence of a sternum, the disposition of the ribs, the
mechanism of the tail, the motion of the eyes, the toes bound up in
opposable bundles, &c.--though he is not entirely correct on some
points. Pliny mentions it, but his account is for the most part a
compilation from Aristotle.
Calmet's description of the Chameleon is curiously minute:--"It has
four feet, and on each foot three claws. Its tail is long: with this,
as well as with his feet, it fastens itself to the branches of trees.
Its tail is flat, its nose long, ending in an obtuse point; its back is
sharp, its skin plaited, and jagged like a saw, from the neck to the
last joint of the tail, and upon its head it has something like a comb;
like a fish, it has no neck. Some have asserted that it lives only upon
air, but it has been observed to feed on flies, catched with its tongue,
which is about ten inches long and three thick, made of white flesh,
round, but flat at the end, or hollow and open, resembling an elephant's
trunk. It also shrinks, and grows longer. This animal is said to assume
the colour of those things to which it is applied; but our modern
observers assure us that its natural colour, when at rest, and in the
shade, is a bluish-grey; though some are yellow, others green, but both
of a smaller kind. When it is exposed to the sun, the grey changes into
a darker grey, inclining to a dun colour, and its parts which have least
of the light upon them are changed into spots of different colours.
Sometimes, when it is handled, it seems speckled with dark spots,
inclining to green. If it be put upon a black hat, it appears to be of a
violet colour; and sometimes, if it be wrapped up in linen, it is white;
but it changes colour only in some parts of the body."
Its changes of colour have been commemorated by the poets. Shakspeare
has--
"I can add colours ev'n to the Chameleon:
Change shapes with Proteus, for advantage."
Dryden has--
"The thin Chameleon, fed with air, receives
The colour of the thing to which it cleaves."
Prior has--
"As the Chameleon, which is known
To have no colours of his own,
But borrows from his neighbour's hue
His white or black, his green or blue."
Gay, in his charming fable of the Spaniel and the Chameleon, "scarce
distinguished from the green," makes the latter thus reply to the taunts
of the pampered spaniel:--
"'Sir,' says the sycophant, 'like you,
Of old, politer life I knew:
Like you, a courtier born and bred,
Kings lean'd their ear to what I said:
My whisper always met success;
The ladies prais'd me for address;
I knew to hit each courtier's passion,
And flatter'd every vice in fashion:
But Jove, who hates the liar's ways,
At once cut short my prosperous days,
And, sentenced to retain my nature,
Transform'd me to this crawling creature.
Doom'd to a life obscure and mean,
I wander'd in the silvan scene:
For Jove the heart alone regards;
He punishes what man rewards.
How different is thy case and mine!
With men at least you sup and dine;
While I, condemned to thinnest fare,
Like those I flatter'd, fed on air.'"
Upon this fable a commentator acutely notes:--"The raillery at court
sycophants naturally pervades our poet's writings, who had suffered so
much from them. Here, however, he intimates something more, namely, the
apposite dispensations to man's acts, even in this world. The crafty is
taken in by his own guile, the courtier falls by his own arts, and the
ladder of ambition only prepares for the aspirant a further fall."[24]
With respect to the air-food of the Chameleon. Cuvier observes that
its lung is so large that, when it is filled with air, it imparts a
transparency to the body, which made the ancients say that it lived
upon air; and he inclines to think that to its size the Chameleon owes
the property of changing its colour; but, with regard to this last
speculation, he was wrong, as we shall presently see.
It was long thought that the Chameleon, like most of the lizard tribe,
was produced from an egg. The little animal is, however, most clearly
viviparous, and not oviparous, although the tales told of the lizard
tribe in the story books are most perplexing. To name a few of them:--1.
The crocodile, which is the largest of the lizard tribe, and has even
attained the size of 18-1/2 ft. in length, is confidently stated as
laying eggs, which she covers with sand and leaves, to be hatched by the
sun; and these have been met with in the rivers Nile, Niger, and Ganges.
2. _Lacerta Gangetica_, unknown to Linnæus, but brought to this country
from Bengal in 1747 by the late Dr. Mead, is said to be furnished
with a false belly, like the opossum, where the young can be received
for protection in time of danger. In this case the egg must have been
hatched in the belly of the animal, like the viper. 3. The alligator,
or American crocodile, lays a vast quantity of eggs in the sand, near
the banks of lakes and rivers, and leaves them to be hatched by the sun;
and the young are seldom seen. 4. The cayman, or Antilles crocodile, has
furnished its eggs to many collections. 5. A salamander was opened by M.
Maupertuis, and its belly was found full of eggs; but in "Les Mémoires
de l'Académie Royale des Sciences" it is stated that, after a similar
operation of the kind, "fifty young ones, resembling the parent animal,
were found in its womb all alive, and actively running about the room."
The tongue is the chief organ for taking the insects on which the
Chameleon lives. By a curious mechanism, of which the tongue-bone is a
principal agent, the Chameleon can protrude this cylindrical tongue,
which has its tip covered with a glutinous secretion from the sheath
at the lower part of the mouth, to the length of six inches. When the
Chameleon is about to seize an insect, it rolls round its extraordinary
eyeballs so as to bring them to bear on the doomed object; as soon
as it arrives within the range of the tongue, that organ is projected
with unerring precision, and returns into the mouth with the prey
adhering to the viscous tip. The wonderful activity with which this
feat is performed, forms a strong contrast to the almost ridiculously
slow motions of the animal. Their operation of taking meal-worms, of
which they are fond, though comparatively rapid, is not remarkable for
its quickness, but done with an act of deliberation, and so that the
projection and retraction of the tongue can be very distinctly followed
with the eye.
The eyes of the Chameleon are remarkable objects; large, projecting, and
almost entirely covered with the shagreen-like skin, with the exception
of a small aperture opposite the pupil; their motions are completely
independent of each other. It adds to the strange and grotesque
appearance of this creature to see it roll one of its eye-globes
backwards, while the other is directed forwards, as if making two
distinct surveys at one time. Its sight must be acute, from the unerring
certainty with which it marks and strikes its prey.
The Chameleons spend their lives in trees, for clinging to the branches
of which their organization is admirably adapted. There they lie in
wait for the insects which may come within their reach; and it has been
thought that, in such situations, their faculty of changing colour
becomes highly important in aiding them to conceal themselves. The
powers of abstinence possessed by this singular race are very great;
and hence, most probably, arose the old fable of their _living on
air_, which was for a long time considered to be "the Chameleon's
dish." One has been known to fast upwards of six weeks without taking
any sustenance, though meat-food and insects were procured for it.
Notwithstanding this fast, it did not appear to fall away much. It would
fix itself by the feet and tail to the bars of the fender, and there
remain motionless, enjoying the warmth of the fire for hours together.
Hasselquist describes one, that he kept for nearly a month, as climbing
up and down the bars of its cage in a very lively manner.
The power of the Chameleon's changing colour long exercised the
ingenuity of the old naturalists. Hasselquist thought that the changes
of colour depended on a kind of disease, more especially a sort of
jaundice, to which the animal was subject, particularly when it was put
in a rage. M. D'Obsonville thought that he had discovered the secret in
the blood, and that the change of colour depended upon a mixture of blue
and yellow, whence the different shades of green were derived; and these
colours he obtains from the blood and the blood-vessels. Thus he says
that the blood is of a violet hue, and will retain its colour on linen
or paper for some minutes if previously steeped in a solution of alum,
and that the coats of the vessels are yellow; consequently, he argues,
that the mixture of the two will produce green. He further traces the
change of colour to the passions of the animal. Thus, when a healthy
Chameleon is provoked, the circulation is accelerated, the vessels that
are spread over the skin are distended, and a superficial blue-green
colour is produced. When, on the contrary, the animal is imprisoned,
impoverished, and deprived of free air, the circulation becomes languid,
the vessels are not filled, the colour of their coats prevails, and the
Chameleon changes to a yellow-green, which lasts during its confinement.
Barrow, in his "Travels in Africa," declares that previously to the
Chameleon's assuming a change of colour, it makes a long inspiration,
the body swelling out to twice its usual size; and as the inflation
subsides, the change of colour gradually takes place, the only permanent
marks being two small dark lines passing along the sides. Mr. Wood
conceives from this account that the animal is principally indebted for
these varied tints to the influence of oxygen. Mr. Spittal also regards
these changes as connected with the state of the lungs; and Mr. Houston
considers this phenomenon as dependent on the turgescency of the skin.
Dr. Weissenborn thinks it not unlikely that the nervous currents may
directly co-operate in effecting the changes of colour in the Chameleon.
Mr. H. N. Turner, writing from personal observation of the phenomenon
in a live Chameleon in his possession, says:--"It has been generally
imagined that the purpose of the singular faculty accorded to the
Chameleon is to enable it to accommodate its appearance to that of
surrounding objects." Mr. Turner's observations do not, however, favour
the idea, but seem rather to negative it. The box in which Mr. Turner's
Chameleon was kept was of deal, with glass at the top, and a piece of
flannel laid at the bottom, a small branching stick being placed there
by way of a perch. He introduced, at various times, pieces of coloured
paper, covering the bottom of the box, of blue, yellow, and scarlet,
but without the slightest effect upon the appearance of the animal.
Considering that these primary colours were not such as it would be
likely to be placed in contact with in a state of nature, he next tried
a piece of green calico, but equally without result. The animal went
through all its usual changes without their being in any way modified by
the colour placed underneath it. The general tint approximated, as may
be readily observed, to those of the branches of trees, just as those of
most animals do to the places in which they dwell; but Mr. Turner did
not observe the faculty of changing called into play with any apparent
object. It is only when the light is removed that the animal assumes a
colour which absorbs but little of it.
Not to go further into the numerous treatises which have been published
on this intricate subject without arriving at a just conclusion, we
refer to the able and interesting paper of Mr. Milne Edwards, for whose
acuteness the solution of this puzzling phenomenon was reserved. The
steps by which he first overthrew the received theories on the subject,
and then arrived at the cause of the change of colour, is shown in the
following results, derived from observing two Chameleons living, and
researches after the animals had died, on the structure of their skin,
and the parts immediately beneath it.
1. That the change in the colour of the Chameleon does not depend
essentially either on the more or less considerable swelling of their
bodies, or the changes which might hence result to the condition of
their blood or circulation; nor does it depend on the greater or less
distance which may exist between the several cutaneous tubercles;
although it is not to be denied that these circumstances probably
exercise some influence upon the phenomenon.
2. That there exist in the skin of these animals two layers of
membranous pigment, placed the one above the other, but disposed in such
a way as to appear simultaneously under the cuticle, and sometimes in
such a manner that the one may hide the other.
3. That everything remarkable in the changes of colour in the Chameleon
may be explained by the appearance of the pigment of the deeper layer to
an extent more or less considerable, in the midst of the pigment of the
superficial layer, or from its disappearance beneath this layer.
4. That these displacements of the deeper pigment do in reality occur;
and it is a probable consequence that the Chameleon's colour changes
during life, and may continue to change even after death.
5. That there exists a close analogy between the mechanism by the help
of which the change of colour appears to take place in these reptiles,
and that which determines the successive appearance and disappearance of
coloured spots in the mantles of several of the cephalopods.
Chameleons are found in warm climates of the old world, South of Spain,
Africa, East Indies. Isles of Sechelles, Bourbon, France, Moluccas.
Madagascar (where it is said there are seven of the species which belong
to Africa), Fernando Po, and New South Wales. In the year 1860, a new
and curiously formed species of Chameleon was brought from the interior
of the Old Calabar district of West Africa, by one of the natives. It is
characterised by three horny processes on the head. Many Lizards have
singular spiny projections on all parts of the body; but this very well
marked species had not been hitherto recorded.
Mrs. Belzoni, the wife of the celebrated traveller in the East, made
some careful observations upon the habits of Chameleons, which are worth
quoting. The Arabs in Lower Egypt catch Chameleons by jumping upon them,
flinging stones at them, or striking them with sticks, which hurts them
very much. The Nubians lay them down gently on the ground, and when
they come down from the date-trees, they catch hold of the tail of the
animal, and fix a string to it; therefore the body does not get injured.
Mrs. Belzoni had some Chameleons for several months in her house, and
her observations are as follows:--
"In the first place they are very inveterate towards each other, and
must not be shut up together, else they will bite each other's tails and
legs off.
[Illustration: CHAMELEONS.]
"There are three species of Chameleons, whose colours are peculiar
to themselves: for instance, the commonest sort are those which are
generally green, that is to say, the body all green, and, when content,
beautifully marked on each side regularly on the green with black and
yellow, not in a confused manner, but as if drawn. This kind is in great
plenty; they never have any other colour except a light green when they
sleep, and when ill, a very pale yellow. Out of near forty I had the
first year when in Nubia, I had but one, and that a very small one of
the second sort, which had red marks. One Chameleon lived with me eight
months, and most of that time I had it fixed to the button of my coat:
it used to rest on my shoulder or on my head. I have observed, when I
have kept it shut up in a room for some time, that on bringing it out
in the air it would begin drawing the air in, and on putting it on some
marjorum it has had a wonderful effect on it immediately: its colour
became most brilliant. I believe it will puzzle a good many to say what
cause it proceeds from. If they did not change when shut up in a house,
but only on taking them in a garden, it might be supposed the change
of the colours was in consequence of the smell of the plants; but when
in a house, if it is watched, it will change every ten minutes: some
moments a plain green, at others all its beautiful colours will come
out, and when in a passion it becomes of a deep black, and will swell
itself up like a balloon, and, from being one of the most beautiful
animals, it becomes one of the most ugly. It is true that Chameleons
are extremely fond of the fresh air, and on taking them to a window
when there is nothing to be seen, it is easy to observe the pleasure
they certainly take in it: they begin to gulp down the air, and their
colour becomes brighter. I think it proceeds, in a great degree, from
the temper they are in: a little thing will put them in a bad humour: if
in crossing a table, for instance, you stop them, and attempt to turn
them another road, they will not stir, and are extremely obstinate: on
opening the mouth at them, it will set them in a passion: they begin to
arm themselves by swelling and turning black, and will sometimes hiss a
little, but not much.