DENTITION. 



349 



gently along them towards the throat, and they are almost 

 imperceptible even to the touch ; but in withdrawing your 

 finger against the points, you feel how excessively fine they 

 are. 



The accompanying illustrations are from nature, and exem- 

 plify the various lengths of jaw in four snakes, not differing 

 very greatly in size. 



~^^Trt^^ 



Four jaws. From Fayrer's T Jianatophidia of India. 



Fig. A. Ptyas mticosus, with simple teeth only. That 

 they are not very regular is probably owing to the stages of 

 growth in those that have replaced others. 



Fig. B. A venomous snake, Biuigams, the ' Krait,' with a 

 fixed fang in front and a few simple teeth behind it. 



Fig. C. Jaw of the cobra, with a longer fixed fang, and 

 one or two simple teeth behind it. 



Fig. D. The shortest jaw of them all, that of the Indian 

 viper Daboia, in which the maxillary is reduced to a mere 

 wedge of bone. These, with four or five reserve fangs, are here 

 folded back ' depressed.' A few palate teeth are also seen. 



Having given a slight sketch of the various forms of 

 dentition, and arrived at 'fangs,' we may recapitulate, in 

 what Nicholson calls 'roughly speaking,' four stages of 

 development in these latter. 



