506 THE SNAKES OF SOUTH AFRICA. 
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. 
WuHyY 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 paralyze 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. 
