nearly all snakes, there is a double row of teeth along the 

 roof of the mouth. These are the palatine teeth. They 

 always form the longest rows. 



The teeth are small and sharp, very like those of a fish. 

 They are not always of the same size ; sometimes the front 

 teeth and sometimes the back ones are longer than the others. 

 They are always directed more or less backwards so that the 

 snake may hold its prey more securely. 



The teeth of the poisonous snakes differ considerably 

 from those of the harmless ones. 



The upf)er marginal row of teeth does not exist. Its 

 place is taken by the poison fang. 



In poisonous colubrine snakes, e.g., the cobra, the fang 

 is more or less fixed, curving backwards and fitting into 

 a depression in the lower lip. 



In the vipers the poison fang is much longer than in 

 the cobra. Its length however is apt to be exaggerated ; it 

 rarely exceeds half an inch even in the largest specimens of 

 vipers. Still, it is too long to be received into a depression 

 in the lower lip like that of the cobra. So there is an 

 arrangement by which, when the mouth is shut, the fang 

 can be made to lie down along the roof of the mouth. When 

 a viper opens its mouth to bite the long fang becomes 

 erect, sticking out almost at right angles to the upper jaw. 



The fangs both of cobras and vipers have a small canal in 

 them through which the poison from the poison gland is 

 injected into the wound made by the fang. In fact the fang 

 of a large viper is very much like the needle of a hypodermic 

 syringe, through which a doctor injects drugs under the 

 skin. The canal in the cobra's fang is a good deal smlaller 

 than that in the vipers but answers the same purpose. 

 The last point to consider is the colouring of snakes. 

 Many people try to rely entirely on the colour of a 

 snake to identify it. Now although the colour is very 



