52 



Chapter VIII. 



PROTECTIVE COLOURATION. 



Among Serpents, Protective and Aggressive 

 colouration is especially noticeable. The following 

 snakes afford the best examples of advantageous 

 colouration : — 



Dryophis Mycterizans. 



Dryophis Pulverulentus. 



The Lycodons. 



Python Molurus. 



Vipera Rusellii. 



Trimeresurus Trigonocephalus. 

 In many cases colouration may be both 

 aggressive and protective. For example, the green 

 skin of the Dryophis Mycterizans enables it to 

 harmonize with the green leaves of the trees, and 

 become almost invisible both to the lizards and 

 young birds it preys on, and also to snake-eating 

 birds and other enemies. 



The Dryophis Pulverulentus, on the other 

 hand, is a nocturnal snake, and resembles the D, 

 Mycterizans in everything but its colour, which is 

 dark brown. Being nocturnal in habit, a green 

 skin would naturally be useless to this snake when 

 hunting, and as it lives in the brown thatched 

 roofs of houses it would be equally useless to it 

 when asleep in the daytime. 

 Protective Another striking example of protective imi- 



Cok)uration tation is the way in which the little Lycodon 

 Auiicus. Aulicus imitates the deadly Bungarus Ceylonicus 

 (Krait). Except for the different shapes of their 

 heads, the two at first-sight are practically indis- 

 tinguishable. Examination shows, however, that 

 the B. Ceylonicus has enlarged hexagonal vertebral 



