GECKOS. 85 



entirely bony in its back part, nor lias it, so to 

 speak, any flooring ; so that when deprived of 

 the softer parts, the cavity communicates with 

 the mouth. The articulation of the jaw is quite 

 backward."* The spinal column is destitute of 

 any bony processes or ^^I'ojections ; the vertebrae 

 are said to be hollowed out, on their anterior 

 and posterior surfaces, into conical cavities, some- 

 what like the vertebrae of fishes. The number 

 of ribs varies according to the species. 



We have said that the skin is easily detached ; 

 when held up to the light, it is seen to be regu- 

 larly furnished with small, delicate, rounded, 

 escutcheon-like bodies, set in its substance. The 

 form and distribution of these bodies are different 

 in different species, and they are found in the 

 skin of the belly, the neck, the head, the thighs, 

 and the tail. 



The colours of the Geckos are commonly 

 sombre, and even lurid ; frequently various 

 shades of grey and brown, more or less irregularly 

 clouded or mottled ; they have the power in some 

 degree of changing their hues, the colours being 

 darker or paler, and the markings becoming visible 

 or evanescent, at will. Some of the small species 

 are marked with bright colours, which are not 

 mutable. Wagler was informed by some travel- 

 lers, that certain GeckotidcB of India become 

 luminous or phosphorescent during the night ; 

 but we know not how far this information is to 

 be depended on. The skin is moulted or sloughed 

 off, at certain times, when that which envelops 

 the head and fore parts of the body is detached 

 first, the separation proceeding gradually to 



* Penny Cyclop., xi. 102. 



