AREAI^GEMENT OF TEETH AND FANGS. 



The arrangement of the teeth and the presence or absence of fangs 

 are of cardinal importance. Every poisonous Snake is provided mth 

 fangs, while, with one exception — and there may be others — that of 

 Psammodynastes puherulentus, innocent Snakes are free from such 

 weapons. The manner in which the efficient and supplementary fangs 

 are attached to the jawbone is well shown in A, B, C, whilst D demon- 

 strates the mode in which the recurved teeth of an innocent Snake 

 are fixed. The relations of the poison fangs and ordinary teeth are 

 still further illustrated in the skeleton heads of the Eussell's Yiper 

 {Daboia Russellii), Bungarus fasciatus, figured in Plate 20, and of the 

 Cobra {Naja tripudians), in Plate 21, contrasted with the dentition 

 displaying the simple fish-like teeth of the non-poisonous Dhamin 

 {Ptyas mucosus) in Plate 21. The fangs are separately figured in A, B, C 

 These are either channelled into a tubular canal, as in the Daboia and 

 Cobra, or only grooved as in the Hydrophis. It is through this tubiilar 

 or grooved fang that the poison is injected from the poison-gland into 

 the tissues of an effectively bitten animal or man. 



