10 



erector muscles, in the poison gland, is there any new or 

 special organ ; in each case there is a clearly marked grada- 

 tion of development.* 



Koughly speaking there are four stages in the develop- 

 ment of poison apparatus : — 



1°. Tlie presence of grooved fangs in snakes which are 

 either unprovided with poisonous saliva or whose venomous 

 quality is so slight that its effect has not been observed."^ 

 (Nearly all the tree-snakes ; the fresh water snakes.) 



2°. The possession of a salivary gland secreting poison 

 and of a grooved tooth in front of the other maxillary teeth. 

 Little modification in the shape or mobility of the maxillary. 

 (The Sea snakes Sydrophidce, and the ElapidcB of Aus- 

 tralia). 



3°. The maxillary is shortened, it contains one fang with a 

 perfect canal, and often one or two simple teeth behind the 

 fang. It possesses a degree of mobility sufficient to raise the 

 fang from a semi-erect to a nearly perfectly erect position ; 

 the angle moved through being less than 45°. (The Indian 

 Elapidce). 



4°. The maxilla is higher than it is long, and contains 

 only one tooth, a fang several times its own length. It is very 



* I am well aware that my opinion is by no means general ; indeed 

 I may say that I have not seen it mentioned by other naturalists ; 

 but this I ascribe to the maze of errors in which our ideas on snakes 

 have so long been enveloped, to the fascination which the marvellous 

 still has, and the few opportunities possessed by European zootomists 

 for investigating the subject. I earnestly beg the medical profession 

 in India to study this subject by dissection of different snakes ; there 

 is a distressing absence of information and our text books of com- 

 parative Anatomy are all but silent on these points to which the 

 hypothesis of Darwin gives especial importance. 



t These snakes have by some naturalists been classed as the 

 section Suspecta between the sections Innocua and Venenosa, 



