﻿COLORATION ^^ 



districts the desert individuals are paler, without or 

 with less distinct markings, as compared to the^r 

 fellows among other surroundings. In addition to 

 their markings, some snakes are adorned with a 

 metallic iridescent gloss*, due to a fine striation of 

 the scales. 



The iris is often metallic, gold, bronze, or copper- 

 red, and the black streaks of the head sometimes 

 extend over it. 



Although, unlike many lizards, snakes are unable 

 to rapidly alter their colours, some produce a 

 semblance of this phenomenon when inflating their 

 neck or body ; this is due to the presence of dark 

 and light markings or of a bright pigment in the 

 interstitial skin, which is not seen when the scales 

 overlap. Thus, in the Indian Tree-snake Dryophis 

 mycterizans the skin between the green or brown 

 scales in the anterior part of the body is black 

 and white, producing a striped pattern when the 

 neck is inflated ; the skin of the same region is 

 bright vermilion in the Malay Tvopidonotus sub- 

 mini attis ; many more examples could be quoted. 

 The spectacle marking on the hood of the Indian 

 Cobra involves the scales as well as the interstitial 

 skin. 



As a rule there are no sexual differences in colour. 

 Yet these are so marked in our Common Adder that 

 the sex of a specimen can nearly always be recog- 

 nized hy the coloration. This is, however, the 



