GECKOS, LIZARDS, AND CHAMELEONS 79 



the power of indenting steel with the teeth ! In 

 Egypt so intense is the dread in which the lobe- 

 footed species is held, that it is known as the 

 "father of leprosy." 



The Geckos are plump in shape, mostly 

 sombrely coloured, and flat-headed. The skin is 

 mostly covered with small granular tubercles, 

 but regularly arranged scales are rarely present,, 

 save in the under-surface. Two genera, however, 

 have the upper surface of the body also invested 

 in scales, and both these are desert-dwelling 

 types. The skin is shed in flakes and eaten. 

 The eyes are remarkable in that they are 

 not protected by movable eyelids, but by a 

 transparent shield, of the shape of a watch- 

 glass, which is generally regarded as a modified 

 nictitating membrane. Behind this the eye 

 moves freely. The eyelids are reduced to 

 fringes encircling this peculiar cover. This 

 " window " appears to be kept clean by the 

 tongue, which can be protruded for some con- 

 siderable distance. In response to the more or 

 less nocturnal habits of the creature the pupil of 

 the eye contracts into a vertical slit, as in the 

 eyes of cats, for example. 



The tail presents many variations of form. 

 Generally cylindrical, and tapering to a point, 

 it is in some forms leaf -like, as in the fimbriated 

 Gecko ( Uroplates-fimbriatus) for example ; or pro- 

 vided with lobes, as in the Fringed-Gecko 

 (Ptychozoum homalocephalum) but in many desert 

 forms the tail is long, slender, and laterally com- 

 pressed. In some species it is more or less 

 prehensile. 



