CHAPTER XIX. 



DENTITION. 



IN the preceding pages it may have been observed that the 

 adage, ' There are no rules without exceptions,' occurs 

 so frequently in ophidian physiology that the latter are 

 almost in the majority. Concerning the teeth especially, the 

 forms of dentition in the various families, the distinction of 

 species by them, the size and position of poison fangs, etc., the 

 rules involve so many exceptions that we can perhaps render 

 the subject less perplexing by dispensing with rules altogether. 

 * The gradations of teeth are very imperceptible,' said Prof 

 Huxley in his lecture at the London Institution. So numerous 

 are their stages of development that there is really no well- 

 defined gap between the venomous and the non-venomous 

 species. ' We do not know for certain whether the ordinary 

 teeth are poisonous or not,' Huxley also said. The recent 

 researches into the nature of salivary secretions will throw 

 more light on this subject. A large non-venomous snake, 

 like other normally harmless animals, if biting angrily, with 

 its abundant salivary glands pouring secretions into its 



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