11 BRPBTOLOGY. 



29 



H 



(.; . 



best known specie* ha* ton* been celebrated, both in 

 ancient and modern time*, fur the variety of colours 

 which it assume* on different occasions. Their akin is 

 remarkaMy thin and delicate, and i* so loose and dila. 

 table, especially about the belly, as to admit of consi- 

 derable inflation when the animal* expand their ample 

 lungs by a long and deep inspiration. Their eyes are 

 remarkable, both for the membrane that covers them, 

 and for die ease with which they are directed at the 

 same time towards different objects. The peculiar struc- 

 f their feet, and their prehensile tail*, senre to give 

 them a surer bold of the branches of trees in which 

 they generally lire, and thus secure them against the 

 attack* of serpents, by whom they are eajferly sought 

 after, while their long extensile and glutinous tongue 

 enable* them more easily to catch the insects which 

 form their natural food. From the amallness of these 

 insects, and the long abstinence which the chameleons 

 are able to sustain, it was long believed that these ani- 

 mal* lived upon air: vulgar error, which ha* given 

 birth to many a pretty expression among our poets. 

 It has also been supposed, that chameleons assume the 

 colour of any object on which they are laid. This is so 

 far true, that if the object be green of any shade, aa 

 men is the prevailing colour of the chaiaeleon, and as 

 it passn through various hades of this colour when 

 plsasfrf or angry, hungry or satiated, it acquires, in the 

 i of the experiment, a shade very near that of the 

 or doth on which it it laid 'it never become* 



auite blue or quite white, though it often verges upon 

 nets) colour* ; and sometimes the shade of green is so 

 dark, that a hasty observer might call it black. 



Attempts have been maifc t account for the changes 

 of colour in the chameleon, by the remark, that the 

 blood ofthi* animal is of a violet blue, while the natu- 

 ral colour of the skin is yellow ; hence, when the skin 

 i* most transparent, and the animal in greatest vigour, 

 the shad* of green is darkest, or assumes moat of the 

 brae Ic, when the kin is least stretched, and 



the circulation languid, the colour becomes paler, and 

 verges towards yellow. white, or even brown. 



Chameleons are found chiefly in the tropical climate 

 of the old continent, especially in Egypt and other 

 parts of Africa. They are generally of diminutive siw, 

 the largest not exceeding two feet, from the mtunle to 

 the lip of the Urn"; of which the tail occupies one-half. 



Grxvs X. Gecu. GECKOS. 



animals of this tribe are not so unsightly in their 

 1 eyysaraacs as the* are iisgasthia, m their man. 

 id the noxious mud which they secret*. Their 



The animal* of this 

 external. 



ners, and the noxious fluid which they 

 head i pretty thick, especially at the articulation of the 

 jaw*, where it is bordered with small plates, while the 

 surface of the head is covered with small rounded pro- 

 minent scales ; the mnxxle is taper ; the tongue thick, 

 flat, lightly cleft at its tip, and glutinon, but not ex. 

 tensile ; the eye* resemble those of the chamfkfoas, bat 

 the external opening ef the ear* fa lea* apparent, and 

 the threat i* susceptible of slight inflation. The body 

 if long and thin, a little depressed, and covered with 

 ' small pmsuinent scales ; the tail is generally cy- 

 ical. but in a few specie* flattened ; the feat have 

 five broad toes, flattened along their margins, co- 

 1 on their inferior surface with 



'IV III 1 



lindrical, 



imbricated scales, concealing glandular porrs, from 

 which rxndcs a vrry comxive fluid. Each toe is tip- 

 ped with a small crooked daw. 

 The geckos are found in Sosrtfa America, hi Africa, 



and the East Indies. They live about walls and in Saurian 



trees, feed chiefly on insects, and have so little dread of l*q'"l- j 



mankind, a* familiarly to enter their houses. "V" 

 There are 15 species, arranged under three Section?. 



SECTION I. Gectot. 



Gecko*, properly so called, having the five toes dis- 

 tinct, or a little palmated at their base, the tail cylindri- 

 cal, and the body smooth. 



Specif* I . Gecko f.gyptiaeut. Egyptian or common JJgyptiicu- . 

 gecko. Light ash-grey ; tail for the most part having 1 

 six broad rings at its base ; body rather swollen, and a PLATE 

 little flattened. See Plate CCXCVII. Fig. 13. CCXCVII. 



IJK Geclco ordinaire, Daud. iv. p. 107. Fi > ** 



Lacrrta gecto, I. inn. a Cruel, p. 1068. 



CoiM/mM geelro . ^'\&w. 



Le Gccto, Lacepede, ii. part ii. art. 48. 



A very curious structure ha* lately been detected in 

 the foot of this animal by Sir Kverard Home, Bart. 

 Sir Joseph Banks had often observed at Batavia, that 

 the Gecko comes out in the evening from the roofs of 

 the houses, and walks down the smooth hard po i>lied 

 chunam walls in search of flie*; and it occurred to 

 Sir Everard Home, that this must be done by a conni- 

 vance like that of the Kckinri* remorn, or -iakin_ 

 Having procured from Sir Joseph a large specimen, p,. ATr 

 weighing 5^ ox. be was enabled to ascertain the pecu- i < Xt:v. 

 liar mechanism by which the teet of the animal can F'tJ- 18. 19. 

 keep hold of a smooth surface. The Gecko has five 

 toes, and at the end of each, except the numb, is a 

 very sharp curved daw. On the under surface of each 

 toe are I b transverse slits leading to as many cavities, 

 or pockets, whose depth is nearly equal to the length 

 of the slit which form* the orifice : they all open for. 

 ward*, and the external edge of each epening is serra- 

 ted like a small- toothed comb. The cavities, pockets, 

 and sci i aled edge* are covered with a cuticle. A large 

 oval muscle move* the daw of each toe, and from the 

 tendon* of these large muscles, two sets of smaller 

 muscles originate, one pair of which is lost upon the pos- 

 terior surface of each of the cavities that lie immediately 

 over them. The large muscles draw down the claws, 

 and necessarily stretch the imall muscles. \Vhcn tin- 

 small muscle* contract, they open the orifices of the 

 cavities, and turn down their serrated edge upon the 

 surface on which the animal stand* By this mean, 

 vacua are formed, and the animal adhere* to the surface 

 by the pressure of the atmosphere. See Phil. Trans. 

 p. 149. and page 41, col. 8. of this article. 



larrit. Smooth G. Ash grey, all the scales i.vu. 

 very minute, mside of the thigh* not porous ; tail of 

 moderate length, simple at the base; tips of the toes 

 triangular. 



Ii. line fAmrntjur, Daud. iv. p. 11 2. 



S. G. fpinictmda. Spine-tailed G. Body smooth ; Spinicauda. 

 tail nearly the same length a* the body, thick, and ring. 

 ed at the base ; rings beset with spines on each side. 



Le G. a queue epmtute, Daud. iv. p. 1 1 ;,. 



4. G. K *Uat**. Dotted G. Pale ml above, with Guiuw*. 

 small round whitiih spots disposed in rows ; numerous 

 square scale* upon the tail. 



/ G. a goutlelellet blatchei, Daud. hr. p. 1 22. pi. xlix. 



5. G. Siirinainrrui*. Surinam G. Tail as long as s... 

 the body with brown bands, a yellowish band border- ,. 

 ed with brown running from the eye* to the thighs ; 

 back marbled with little brown spot*. 



I* G tie Surinam, Daud. iv. p. 126. 



. G. jtorpltyretu. Porphyry G. Pale red-brownish Porphrmu. 

 above, with numerous small round spots of a paler hue. 



