510 THE SNAKES OF SOUTH AFRICA. 



stand fifteen minutes. It was then injected into the muscles of 

 a large fowl. Three drops of Puff Adder venom were at the same 

 time mixed with some pure water and injected into another fowl. 

 Both fowls manifested the same symptoms of poisoning and died 

 within five or ten minutes of each other. 



Other more or less similar experiments were made, but in all 

 cases the treatment with the ammonia solution did not delay death. 

 The symptoms were the same as those shown by the control animals 



Being desirous of ascertaining if pure ammonia would in any 

 way destroy the poisonous properties of snake venom, I mixed 

 a teaspoonful of the strongest liquid ammonia with three drops 

 of Puff Adder venom and allowed it to stand for half an hour. 

 The solution was then dissolved with one-half water and injected 

 into the muscles of a large cock fowl. The symptoms of poisoning 

 developed in the usual manner, and the fowl died, the ammonia 

 not, apparently, delaying death in the least. From this experi- 

 ment it was made evident that even the strongest ammonia 

 exerted no venom-destroying power, even when actually mixed 

 in solution with the poison. 



K. 

 Why do Snakes' Fangs Differ in Length ? 



Why should the Adder family of snakes have long curved 

 fangs, and those of the Cobra family be so comparatively small ? 

 This problem vexed my mind. Nature has a fixed and definite 

 purpose in all she does. Those great fangs of the Puff Adder 

 were not evolved without a distinct purpose. True, they enable 

 the reptile to inflict severe mechanical injuries upon the small 

 creatures which are the prey of these snakes. But then, why 

 should not the Cobras have also evolved large recurved fangs, 

 for their prey also consists of the same species of creatures. 

 The viper often grips its prey and holds on till the creature is 

 dead. So also do the Cobras and other venomous Colubrine 

 snakes. At other times they strike and instantly withdraw 

 their fangs, relying upon the venom to paralyse their victim 

 before it can escape out of their reach. 



The fangs of a large Cobra are only about a quarter of an 

 inch long, while those of a Puff Adder are three-quarters of an 

 inch in length. When the Cobra delivers a full bite, the venom is 

 shed, mostly on the muscles just under the skin. The Puff Adder, on 

 the contrary, drives its fangs deep down into the muscular tissue. 



