CiiAMEi,EONS. REPTILES. Chameleons. 83 
its Tipwavd gaze ; presently a fly appears, one eye 
rapidly and interestedly follows all its movements, 
while the other leisurely glances hither and thither, or 
remains steady. Accustomed as we are to see in 
almost all animals the two eyes move in unison, this 
want of sympathy produces an effect most singular and 
even ludicrous.” The Chameleons have a very large 
mouth. When shut, it is closed so exactly that we 
can scarcely distinguish the line which indicates the 
separation of the jaws, though in reality it is deeply 
cleft. The teeth are sharp-cutting, with three lobes, 
forming a single line or series upon the sharp edge of 
each jaw. There are none on the palate. The tongue, 
however, is the most extraordinary organ in the body, 
and indeed, as a piece of mechanism, is unique. In a 
state of repose, and when contained in the mouth, it 
forms a round fleshy tubercle, white and solid, about 
ten lines long, three in breadth, a little flattened at its 
extremitjq and lubricated with a glutinous secretion. 
When, however, it wishes to catch its prey, or to 
quench its thirst with a drop of water, it can launch 
it out from its mouth with extreme rapidity, and to 
a distance as great at least as the length of its whole 
bod}'. When thus protruded, we then see that nine- 
teiiths of its extent consist of a fleshy tube which is 
hollow, and possessed of such great contractility that 
it can be withdrawn with great celerity into the mouth 
again, folding in upon itself, somewhat in the way a 
pocket telescope is shut up. This motion is performed 
without making the slightest noise, and in the twinkling 
of an eye, without any change in the position of any 
other part of the body. Some portions of the internal 
structure of these animals, are no less singular than 
those of the external characters just mentioned. The 
lungs, for instance, deserve a moment’s consideration. 
When empty, they sink down below the heart, like 
two small fleshy masses ; but as soon as air penetrates 
them, they swell out so much that they cover the 
whole of the intestines, and are too voluminous to be 
contained even within the abdominal cavitjn They 
are divided into seven or eight lobes or ajipendages on 
each side, which terminate in points, and these pene- 
trate into the various parts of the abdominal cavity, 
and into the hollows or vacant places already mentioned 
in the skin under the muscles. They thus appear to 
be more or less directly connected with that remark- 
able pro[)erty these animals possess of changing the 
colour of their skin. This property, as we have seen, 
in treating of the Agamas (page 29), is not peculiar 
to the Cliameleons ; and besides, though celebrated in 
fable and in poetry for this faculty, it would appear 
to be much exaggerated. The commonly received 
opinion upon the subject is, that the Chameleon 
assumes the colour of any object upon which it is 
placed, or which may be presented to it. 
Mr. Martin informs us that numerous living speci- 
mens of the Chameleon had come under his observa- 
tion. “ To say what is the natural colour of the 
Chameleon is rather difficult; that which was most 
permanent in the animals we have seen was a dull 
yellowish, tinged with a livid hue ; the latter pre- 
vailing more especially on the limbs. Sometimes, 
however, the universal colour was a straw-yellow. 
VoL. 11. 6 1 
When the animals were teased or irritated, the lungs 
seemed to empty themselves, the sides collapsed, every 
rib became visible, and the colour changed to dark 
livid. AVhen in good health, and enjoying the warmth 
of the sun to which these animals are very partial, 
delighting to bask for hours in the genial rays, the 
yellow of the skin became changed into a delicate 
green ; but not always so, for sometimes the skin 
appeared spotted with yellow upon a dull greenish- 
gray, and at other times marbled with olive and straw 
colour. The changes were in general instantaneous, 
especially from a light to a dark tint ; at other times 
the transition was more slow ; and this was the case, 
as it appeared to us, when the skin became marbled or 
mottled. As night came on the tints became more 
dull, and the general hue was frequently a dusky 
olive or a dark grayish -brown, not unfrequently tinged 
with blue.” Several observers have noticed the curious 
fact that sometimes onl}' one side of the animal changed 
colour. Mr. Slight, in a short account of two Chame- 
leons which lived for some time in his possession, saj's 
that he had often seen one side of a stone colour 
and the other a black green. Dr. Weissenborn, who 
had for some months a Chameleon in his possession, has 
also recorded the fact, and attempts to account for it 
by the efiect of involuntary galvanic or nervous cur- 
rents, distinct from each other, independent of each 
other, and occupying separate halves of the body ; the 
remote cause being the way in which the light acts 
upon the animal. Another curious circumstance with 
regard to the change of colour in this animal, is, that it 
never assumes a quite white nor a pure red colour. It 
seems also, from some accounts given us, that it has a 
strong antipathy to things of a black colour. Forbes, 
in the “ Oriental Memoirs,” tells us that one which he 
kept, uniformly avoided a black board which was hung 
up in the chamber; and what is more remarkable, when 
it was forcibly brought before the black board it trem- 
bled violently and assumed a black colour. Various 
theories have been promulgated to account for this 
phenomenon, the change of colour. M. Milne Edwards 
states that there exist in the skin two layers of colour 
called pigment. The deeper-seated is of a deep green 
or violet-red colour, while the superficial layer is of a 
grayish hue. The deep-seated pigment is contained 
in branched cavities, and is movable. Sometimes 
these two appear blended together, while at others, 
one entirely conceals the other; and thus by their 
partial accumulation and varying proportions, the 
changes of colour are produced. In addition to this, 
Dr. Weissenborn believes that these pigments must 
possess of themselves the faculty of changing their 
hues, as no mechanical mixture, he says, of two given 
colours could produce those various tints which the 
skin of the Chameleon exhibits at different times. 
THE COMMON CHAMELEON iChameleo vulgaris) is 
a native of India and Africa. It occurs in Egypt and 
in Northern Africa, and is the species which has been 
naturalized in Southern Europe. It has thus, above 
all others, afforded opportunities for observation when 
alive. It is represented with its tongue launched out, 
in Plate 3, fig. 2, and Plate 8, fig. 4. This Cliameleon 
was well known to the ancients, who believed it lived 
