34 INTRODUCTION 



great importance cannot be attached to the number 

 of the markings, for systematic purposes. In fact, 

 in some Coral-snakes, Elaps fulvius for instance, the 

 number of annuli may vary from twelve to fifty-two, 

 with every gradation between the extremes. The 

 bilateral asymmetry to which we have alluded pro- 

 duces the chess-board arrangement of the ventral 

 spots in many snakes. 



Among the markings which call for investigation 

 as to their meaning, we must allude to the presence, 

 in some Colubrids, of a small, light, dark-edged spot, 

 or of a pair of light dots close together, in the 

 middle of the parietal shields or on each side of the 

 suture between these shields, which correspond in 

 their position to the parietal organ of many Lizards. 

 May not this marking be in some way correlated 

 with sensory organs, like the apical pits on the scales 

 of the body ? And what is the explanation of such 

 bizarre signs as the spectacle or the eye-spot on the 

 hood of the Indian Cobra ? At present it is as 

 inexplicable as the lugubrious emblem on the thorax 

 of the Death's-head Moth. It cannot be suggested 

 that it is a warning mark intended to terrify intruders, 

 for when the Cobra is at rest the hood is folded, and 

 the characteristic marking is not displayed ; whilst 

 as soon as it is aroused, and the hood expanded, it 

 faces its enemy in such a way that the spectacle, or 

 ocellus, is not to be seen. 



First among the most brilliantly coloured snakes, 



