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AIDS TO THE DIFFEKENTIATION OF SNAKES. 

 By Capt. F. wall, I.M.S. 



IRead before the Bombay Natural History Society on 18th February 1902.) 

 The most important factor in popularising and thereby advancing a sub- 

 ject lies in simplifying it, so that the veriest novice may grasp it with ease 

 instead of suffering discouragement at the threshold of his enquiries, as is so 

 often the case, I have frequently, in India, seen a man bring some natural 

 history object to identify which has aroused his interest. He borrows a 

 book, but though he knows the creature is probably described therein, he is 

 at a loss to know where to be^in his search. He discovers a key, however 

 and gaily sets to work. Sooner or later, he is frequently confronted with 

 some unintelligible technicality, or what is worse, finds that he has to unravel 

 some detail which perhaps only a careful and skilful dissection, or the pre- 

 paration of a skeleton, will elucidate. At such a point his enquiries must, in 

 many cases, come to a dead-lock, and it is not surprising that he throws down 

 the book disgusted and has to resign himself to a further term of ignorance 

 till, perhaps, some friend (not always forthcoming) can give him the inform- 

 ation he requires and help him through the intricacies of identification. 



There are scores of men in India with a bent towards natural history in 

 some branch or another, many of whom have abundant leisure and abundant 

 opportunities for observation, and who would welcome a hobby that would 

 relieve camp life of some of its solitude and monotony, and introduce an in- 

 terest throughout many a wearisome journey in the district. Many of these 

 men have made an attempt to acquire information, and have been baffled in 

 their early endeavours owing to the unsatisfactory and complicated nature 

 of some key. 



Many authors, while elaborating the descriptive parts of a work frustrate 

 the object of that work in great measure by bestowing far too little atten- 

 tion to the compiling of the keys, which are really the essential part since 

 It 13 by these that identification is rendered feasible or otherwise. The' book 

 which can afford the surest and most lucid guides to identification is the 

 book that will command the largest sale and produce the most far-reaching 

 and useful results, and it is such a work that so many men feel the want of. 

 If the keys are to be made of real utility, they should be simplified, firstly by 

 purging them of all technicalities, or, where this is impossible, explaining 

 them by diagrams in all cases. Secondly, by discarding reference to 

 pomts which can only be elucidated by investigating anatomical peculiarities, 

 substituting those observed in external characters alone, and always selecting 

 those that can be most easily appreciated and put into practice. Such con- 

 siderations as the plumage of the nestling in birds, the hypapophyses of 

 vertebriB in snakes, &c., &c., though of interest and utility to the comparative 

 anatomist, can have little, if any, practicable value to the generality of know- 

 ledge-seeking individuals, and the mere fact that such abstruse and occult 

 differences are incorporated in the keys, leads one to infer that there is no 



