CHAPTER VI 



COLORATION AND ITS INTERPRETATION 



Colour in relation to environment. Stripes and spots in lizards. Colour- 

 changes in relation to sex and age. Colours of young pit-vipers. Voluntary 

 colour-changes. Green arboreal snakes. Desert-snakes. Sea-snakes. Bark- 

 geckos. Lizards. Warning and protective colours. 



UNLIKE the majority of mammals inhabiting the temper- 

 ate and sub-arctic zones, reptiles do not exhibit a 

 seasonal change of colour ; and for the reason that they 

 do not inhabit the sub-arctic regions, and that those of the colder 

 parts of the temperate regions hibernate. It is noticeable, how- 

 ever, that the young of some reptiles are more brilliantly- 

 coloured than the adults, while snakes display much more vivid 

 hues immediately after changing their skins than at other times. 

 Probably the colours of the great majority of reptiles are pro- 

 tective, that is to say, they harmonise more or less completely 

 with their environment, and thus render the creatures incon- 

 spicuous. For instance, foliage-haunting reptiles such as 

 chamseleons and tree-snakes are coloured green ; while the 

 majority of reptiles inhabiting open ground are either mud- 

 coloured or sand-coloured, as, for instance, crocodiles, stellion 

 lizards, skinks, and desert-snakes. The brilliant coloration of 

 many of the pythons, such as the Malay Python reticulums, 

 appears highly conspicuous in specimens in a museum, but it is 

 probable that among the splashes of sunlight and shade of their 

 native forests these bright-hued reptiles are inconspicuous, the 

 tesselated pattern of the colour breaking up the hard outlines 

 of the body. Again, as is shown later, sea-snakes display 

 adaptive colouring in a marked degree. Before considering in 

 detail these adaptations in general colouring, reference may be 

 made to observations with regard to the occurrence of stripes 

 and spots in certain lizards. 



Many lizards, especially some of the skinks, display a longi- 



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