176 THE SNAKES OF SOUTH AFRICA. 



rearing the fore part of its body perpendicularly above the 

 ground, and expanding the skin of its neck in the well-known 

 manner of Cobras, you may be perfectly sure it is one of the 

 Cobras, and that it is a very highly venomous serpent. 



The Poison Apparatus. 



The Cobra has strong poison fangs in the upper jaw — one on 

 each side with duplicates. These fangs are deeply grooved down 



Fig. 75. — This picture shows the elongated ribs of the neck of a Cobra with 

 the muscle attachments. By means of these long ribs and muscles the 

 hood is spread. The head is on the right. 



their front surface. In some individuals the sides of the channels 

 meet and form hollow fangs. The grooves or channels are for the 

 conveyance of the venom from the poison glands into the wounds 

 made by the fangs. The bite and the compression and contraction 

 of the poison glands is simultaneous. 



The fangs of Cobras are set in front of the upper jaw, in a bone 

 called the anterior maxillary. This bone is not very movable. 

 On the contrary, with the Viper family of snakes it is mobile, and 

 hinge-like in its movements. 



