86 



MUSEUM OF ANIMATED NATURE. 



[Geckos. 



ment. do in reality occur ; and it is a probable con- 

 sequence that the chameleon's colour changes dur- 

 ing 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 changes of 

 colour appear 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." 



How the mechanical admixture of two pigments 

 can produce the various tints, exhibited at different 

 times by the skin of the chameleon, as primary 

 yellow and red, yellowish grey, brown and violet, or 

 dull inky blue, is not very clear. Must not the 

 pigments themselves change colour ? We think 

 so. 



The skeleton is remarkable for the strong spinous 

 processes of the vertebral column ; the number 

 of the cervical vertebrse is only five (the majority 

 of Sauna having eight) ; it is represented at Fig. 

 2142. 



Fig. 2143 represents the Head and Tongue of the 

 Chameleon in the act of taking prey. 



As all its form indicates, the chameleon is arboreal 

 in its habits ; it traverses the twigs and branches in 

 a slow and cautious manner, clinging by the tail, 

 and grasping with its feet ; on the ground its 

 motions are awkward and irresolute, and it gropes 

 about, using its limbs in succession rather than 

 in pairs. 



We have had abundant opportunities of observing 

 the chameleon in captivity, and cannot say that it 

 is very attractive. It is slow and inanimate, ever 

 seeking the warmth of the sun, in the rays of which 

 It wili bask for hours together, changing its tints as 

 evening draws on, and assuming with darkness a 

 dusky hue. In a hothouse, it will live among the 

 plants, as if in a state of perfect liberty, but never 

 displays any intelligence or activity. 



The female digs an excavation in the ground for 

 the reception of her eggs, and covers them with 

 earth and dried herbage. The eggs are numerous, 

 and oval, and covered with a tough semicalcareous 

 sort of parchment. 



2144. — The Common Chameleon 



(Chamceleon vulgaris). This species is a native of 

 Egypt, and the northern line of Africa, and also the 

 southern districts of Spain and Sicily. It was well 

 known to the ancients, and is the ;^u/utixiut of 

 Aristotle. 



A distinct variety, or nearly allied species, in- 

 Iiabits India. 



Dr. Weissenborn, who had a chameleon for some 

 months in his possession, remarks, that of all the cir- 

 cumstances connected with the variations of its 

 colour, none were more surprising than the differ- 

 ence between the tint of one side of the body and 

 that of the other at the same time ; and he attributes 

 this to separate galvanic or nervous currents, di- 

 rected independently of each other to the two sides 

 of the body. 



His words are : " The remote cause of the differ- 

 ence of colour in the two lateral halves of the body 

 may be distinctly referred to the manner in which 

 the light acts upon the animal. The statement of 

 Murray, that the side turned towards the light is 

 always of a darker colour, is perfectly true ; this 

 rule holds good with reference to the direct and 

 diffused light of the sun and moon as to artificial 

 light. Even when the animal was moving in the 

 walks of my garden, and happened to come near 

 enough to the border to be shaded by the box 

 edging, that side so shaded would instantly become 

 less darkly coloured than the other. Now, as the 

 light in these cases seldom illumines exactly one 

 half of the animal in a more powerful manner than 

 the other, and as the middle line is constantly the 

 line of demarcation between the two different shades 

 of colour, we must evidently refer the different 

 effects to two different centres, from which the 

 nervous currents can only radiate, under such cir- 

 cumstances, towards the organs respectively situated 

 on each side of the mesial line. Over these centres, 

 without doubt, the organ of vision immediately pre- 

 sides : and indeed we ought not to wonder that the 

 action of light has such powerful effects on the 

 highly irritable organization of the chameleon, con- 

 aidering that the eye is most highly developed. 

 The lungs are but secondarily affected, but they 

 are likewise more strongly excited on the darker side, 

 which is constantly more convex than the other. 



" Many other circumstances may be brought for- 

 ward in favour of the opinion that the nervous 

 currents in one half of the chameleon are going on 

 independently of those in the other ; and that the 

 animal has two lateral centres of perception, sen- 

 sation, and motion, besides the common one in 

 which must reside the faculty of concentration. 

 Notwithstanding the strictly symmetrical structure 

 of the chameleon, as to its two halves, the eyes 

 move independently of each other, and convey dif- 



ferent impressions to their different centres of per- 

 ception : the consequence is, that when the animal 

 is agitated, its movements appear like those of two 

 animals glued together. Eacn half wishes to move 

 its own way, and there is no concordance of action. 

 The chameleon, therefore, is not able to swim like 

 other animals : it is so frightened if put into water, 

 the faculty of concentration is lost, and it tumbles 

 about as if in a state of intoxication. On the other 

 hand, when the creature is undisturbed, the eye 

 which receives the strongest impression propagates 

 it to the common centre, and prevails upon the 

 other eye to follow that impression and direct itself 

 to the same object. The chameleon moreover may 

 be asleep on one side and awake on the other. 

 When cautiously approaching my specimen at 

 night, with a candle, so as not to awaken the whole 

 animal by the shaking of the room, the eye turned 

 towards the flame would open and begin to move, 

 and the corresponding .side to change colour, 

 whereas the other side would remain for several 

 seconds longer in its torpid and changeable state 

 with its eye shut." (See ' Magazine of Natural 

 History,' October, 1838, p. 632.) 



These views of Dr. Weissenborn are worth con- 

 sideration; fuller details will be found in the work 

 referred to. 



Fig. 2145 represents the Skull, in two views, of 

 the Fork-nosed Chameleon (Chamseleon bifidus). A 

 native of the continent of India, the Moluccas, 

 Bourbon, and also of Australia. The top of the 

 head is flat, the muzzle is prolonged into two 

 distinct branches, which are compressed and den- 

 telated along the upper and under margins. In its 

 general manners this strange species agrees with 

 the rest of its congeners, and we cannot imagine 

 the end to be answered by the singular conforma- 

 tion of the snout. 



Family GECKOTIDiE (GECKOS). 



Like the Chameleons, the Geckos form a distinct 

 and very natural family. They are reptiles of small 

 size, but of repulsive aspect and of nocturnal habits ; 

 from the structure of the toes they are capable of 

 running along the smoothest surfaces, up walls, and 

 even, like a fly, of traversing ceilings; they lurk in 

 the chinks and fissures of walls and trees, in holes 

 and crannies, under the broad leaves of trees, and 

 in some countries infest the habitations of man. 

 They are universally distributed through every 

 quarter of the globe, but are most numerous in the 

 warmer climates of Asia. Two species are common 

 in Southern Europe, and occur also in Northern 

 Africa. The species are numerous. 



We have said that the aspect of these lizards is 

 uncouth. The head is large and flat, the neck 

 short, the body thick and depressed, without any 

 dorsal ridge ; the limbs are short and stout, the toes 

 are of almost equal length, flattened, and expanded 

 beneath, and transversely laminated, or furnished 

 with imbricated suckers, by means of which they 

 adhere firmly in any position; and the claws are 

 sharp, hooked, and retractile, like those of a cat. 

 The eyes are large, full, and bright, generally with 

 a narrow linear festooned pupil, which expands at 

 night. The eyelids are little developed, while the 

 eyes have a staring glance. The orifices of the 

 ears are placed on the sides of the head, the tym- 

 panic membrane being considerably below the sur- 

 face, and the orifice bordered by two folds of skin. 

 The tongue is large and fleshy, but slightly pro- 

 tractile, and its free extremity is either notched or 

 rounded. The teeth are small, equal, compressed, 

 with cutting edges, and implanted in the internal 

 aspect of the jaws. There are no palatal teeth ; the 

 ' mouth is wide. The skin is granulated, and often 

 beset with scattered tuberculous scales ; and the 

 limbs, the sides of the body, and tail, are sometimes 

 fringed with dentelated or vandyked membranes. 

 In the males generally, and often in the females, 

 there is a line of pores (femoral pores) on the in- 

 side of each thigh, and across the lower part of the 

 abdomen. The tail is variable in length, but never 

 exceeds that of the body. 



The tints of these reptiles are mostly blended 

 greys and browns ; but it would appear that, as in 

 the chameleons, they are capable, to a certain ex- 

 tent, of changing their hues, transient shades of 

 blue, red, and yellow appearing and disappearing 

 at the creature's will ; and, according to Wagler, 

 certain Indian species become luminous or phos- 

 phorescent during the night. From the flatness 

 and flexibility of the body, these reptiles are ca- 

 pable of insinuating themselves into the smallest 

 crevices, and their sombre hues blending into and 

 harmonizing with the shadowy obscurity in which 

 they are, so to speak, enveloped during their hours 

 of retirement, tend to their concealment. They 

 off'er nothing to attract the eye, no movement, no 

 brilliant colour. 



At night they come forth all alive in quest of in- 

 sect prey, ever and anon uttering their clucking cry, 

 whence the imitative name Gecko, and also Tociaie 



and Geitje. Their bright eyes glare ; they traverse 

 craggy rocks, old walls, and the rough trunks of trees 

 exploring every crevice: they lurk in ambush, and, 

 dart from their concealment upon their victim ; 

 they appear and vanish as if by magic ; we see them 

 and the next moment they are gone. Confident in 

 their powers, they boldly await approach, their eyes 

 gleam, and their fixed gaze seems to bid defiance ; 

 you raise your hand to strike or seize them ; where 

 are they ? not a rustle was heard, not the slightest 

 noise, and yet they have disappeared. Thus en- 

 dowed, and of forbidding aspect, we can scarcely 

 wonder at the aversion entertained towards these 

 reptiles in the countries they tenant. They are re- 

 garded as being extremely venomous, and it is be- 

 lieved that even their touch occasions malignant 

 disorders of the skin, while their saliva is most 

 dreadfully noxious. "They are reported to ])oison 

 viands of any kind over which they may crawl , render- 

 ing such highly deleterious. It often happens that in 

 these popular errors there is some degree of' truth. 

 The toad, for example, is said to be venomous, and 

 there is some degree of truth in the assertion. The 

 cutaneous glands pour forth an irritating acrid se- 

 cretion, and several times have we seen a dog seize 

 one of these creatures, but instantly drop it, and 

 retreat shaking his head, while the foam filled his 

 mouth and ran down the jaws, his distress lasting 

 for hair an hour; a favourite spaniel of ours was 

 once served this trick, but nothing would induce 

 him afterwards to approach such " varmint," though 

 he would kill a rat in an instant. 



So it is with these calumniated geckos ; their 

 sharp clinging claws, and the suction of their toe- 

 pads, acting like little air-pumps, will really produce 

 redness on a delicate skin, and it is not unlikely that 

 an irritating secretion may contribute to this, besides 

 combining with the slight puncture of the claws 

 and the suction of the pads to produce marks for 

 some time permanent : this is the key-note to the 

 strain of the horrible which runs current. 



Like many other lizards, our own pretty little 

 common lizard (Zootoca vivipara) for instance, the 

 geckos have the singular power of reproducing 

 their tail when lost by accident. The tail, indeed, 

 is very brittle, and when broken off it is soon re- 

 newed, but a swelling marks the line where the re- 

 produced member commences ; many such examples 

 in the different species of gecko have come under 

 our personal notice. 



The Gecko, or rather one species, was well known 

 to the ancients, and it is generally admitted that it 

 was the lizard described by Aristotle under the 

 name of Ascalabus or Ascalabotes (a«-«i<xa/3»,-, sive 

 MxaXa^Tue), and by Pliny under that of Stellio. 

 This opinion was supported by the learned Gesner, 

 who has shown that under the names of Ascalabotes 

 and Galeotes, both Aristotle and Theophrastus spoke 

 of the little lizards, which in his time the Italians 

 designated by the name of Tarentola, and which 

 are characterized by a short squat body, climbing 

 the walls of buildings and the sides of rooms in 

 quest of spiders, on which they feed. Schneider, 

 who has published an express dissertation on the 

 subject, has satisfactorily demonstrated the identity 

 of the Stellio of Pliny with the Wall Gecko of South- 

 em Europe and Northern Africa (Platydactylus 

 muralis, Bibr. ; Lacertus facetanus, Aldrovand). 



Fig. 2146 represents the Skull of the Gecko : a, 

 the cranium ; b, the lower jaw ; c, a tooth enlarged. 



The Geckos are divided into various genera ac- 

 cording to the structure of the feet, of which some 

 of the principal forms are displayed at Figs. 2147 

 and 2148. 



In these representations the object marked with 

 the numeral only displays the foot, those with the 

 letter a added exhibit the structure of the lower 

 part of the toe. Fig. 2147 : 2, Piatydactylus cepe- 

 dianus ; 3, Platydactylus yEgyptiacus ; 4, Platydac- 

 tylus guttatus (Gecko verus. Common Gecko of 

 Gray) ; 5, Platydactylus homalocephalus (Ptycho- 

 zoon of Kuhl, Pteropleura of Gray) : 6, Platydac- 

 tylus Leachianus (Ascalabotes Leachianus, Griff. 

 An. Kingd.) ; 7. Hemidactylus oualensis (Peropus, 

 Weigmann) ; 8, Hemidactylus triedrus. 



Fig. 2148 ; 2, Thecadactylus the conyx ; 3, Ptyo- 

 dactylus Hasselquistii (P. guttatus, Rupp'ell); 4, Ptyo- 

 dactylus fimbriatus; 5, Phyllodactilus porphyreus; 

 6, Gymnodactylus scaber (Stenodactylus, Riippell ; 

 Cyrtodactylus, Gray) ; 7, Gymnodactylus pulchellus 

 7 b, the claw of the latter in profile. 



2149. — The Smooth-headed Gecko 



(^PkUydactyhis homalocephalus). This singular 

 reptile is a native of Java, and is remarkable for 

 a free membrane which borders the sides of the 

 head, the sides of the limbs, body and tail, and 

 which is deeply vandyked or indented on the 

 latter. The general colour above is brown, with a 

 yellower tint down the back, which is divided at equal 

 distances by black wavy lines, while a zigzag line 

 encircles the top of the head ; the membranes and 

 under parts are whitish. Of its habits nothing is 



