On removing the skin from the cheek and lips of a harm- 

 less snake the first structure to be observed is the long 

 ligament leading from the back of the maxillary to the 

 tympano-mandibular articulation ; this ligament is in reality 

 formed by a thickening of the fascia covering the temporal 

 muscles. These muscles are the superficial and posterior 

 temporal muscles and the tympano-mandibular ; on removing 

 them the deep temporal is seen, its two heads divided by the 

 maxillary nerve. The large lacrymal gland is also exposed 

 on removal of the superficial muscles. 



The maxillary is suspe^nded posteriorly by the jugal 

 ligament (a structure corresponding perhaps to the zygoma 

 in man) to the postfrontal bone ; in venomous snakes this 

 ligament becomes of considerable importance. The muscles 

 of the palato-pterygoid region are covered by the rugate 

 mucous membrane of the mouth and pharynx ; on removing 

 this, we expose the muscles, and also, between the palatine 

 and maxillary rows of teeth, the floor of the orbit ; in this 

 space the maxillary vessels are seen. 



CHAPTER III. — The Mouth and Teeth of Venomous 



Snakes. 



To the disciple of Darwin the modifications we are about 

 to study have been developed by natural selection. Several 

 harmless snakes have long simple fangs for the purpose of 

 holding tough-skinned prey, others, including nearly all the 

 tree-snakes, have grooved fangs, though, as far as we know, 

 •without any modification in the quality of the saliva. With 

 these facts before us, and with the knowledge that in 

 some animals the saliva becomes poisonous under certain 

 conditions, there can be little difficulty in accounting for 

 the development of the most perfect poison-apparatus. 

 Neither in the fangs, in their mucous envelopes, in their 



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