SNAKES. 129 



Internally, before the arrival of the doctor, small 

 doses of alcohol may be given. 



The Common Viper may generally be distin- 

 guished from the Grass-snake by reason of the 

 diamond-shaped pattern which runs down the 

 back and the ^-shaped bar on the head. The 

 females are larger than the males. 



Certain mammals and birds are immune by 

 nature against snake-bites : such are the Hedge- 

 hog, the Pig ; and the Secretary-bird, Honey- 

 buzzard, and Stork. 



It should be remembered, in justice to these 

 dreaded and much abused creatures, that their 

 poisonous properties are directed mainly to the 

 capture of food. Man falls but too often a 

 victim to their virulence because he threatens 

 their safety, or invades their dominions. 



One of the most remarkable adaptations for 

 feeding to be found among the Yertebrata is that 

 of the Egg-eating Snake (Dasypeltis scabra) of 

 tropical and South Africa. The jaws are 

 almost toothless, since large teeth would pro- 

 bably break the egg-shell and so waste the 

 contents. The egg is accordingly swallowed 

 whole, and, having passed the head, forms a 

 huge swelling immediately behind. After a few 

 slight contortions the swelling suddenly col- 

 lapses, and later the shell and its inner lining, 

 neatly rolled up, are ejected from the mouth, 

 like the indigestible pellets of birds of prey. 

 Dissection of the creature shows that the teeth 

 of the jaws have been replaced by teeth in the 

 throat formed by downwardly directed spines 

 from the vertebral column, which, piercing the 

 I 



