348 THE SNAKES OF SOUTH AFRICA. 



Four drops of Puff Adder venom is enough to cause such 

 extensive haemorrhage into the tissues of a man as to kill 

 him. Unless driven deep into the muscular tissue, a healthy 

 man would in the majority of cases recover. It would take a 

 subcutaneous injection of five to six drops to cause certain death. 



In a man whose blood is altered by habitual indulgence in 

 alcohol even in moderation, less than a drop might suffice to 

 kill him. In monkeys which have been given a fair quantity of 

 alcohol daily for a month, a drop of Puff Adder venom is 

 sufficient to kill them. Often the site of the injection turns 

 black. This mortification of the tissues at the site of the entry 

 of the venom, spreads into the body and causes death. 



Discharging Venom. 



It is stated that the act of gaping the jaws and erecting 

 the fangs causes an automatic action of the muscles controlling 

 the poison glands forcing the venom out. This is not so. The 

 poison is not expelled every time the snake gapes its jaws. 



Puff Adders frequently yawn, gaping their jaws widely. 

 Sometimes both fangs are erected to their fullest extent. At 

 other times, the snake raises and depresses them in turn. This 

 is done carefully and deliberately, seemingly for the purpose of 

 exercise. The occasional raising of the fangs evidently gives 

 some measure of relief or satisfaction to the snake. It is rare 

 for Cobras to yawn, except after a meal. The Adders do it at 

 various times. 



When artificially feeding Puff Adders, venom frequently 

 squirts from the fangs when the mouth is forced open and the 

 fangs erected. In these cases, the reptiles are naturally in a 

 state of irritation. This causes the constriction of the glands 

 the instant the fangs assume the erect posture. At these feeding 

 times I have collected as much as eleven drops of venom from a 

 single Puff Adder. 



Care has to be exercised at feeding times to hold the snake's 

 head in such a position that the fangs point away from the faces 

 of the operators. My assistant one day received a full charge 

 of venom over his mouth, moustache, and chin. Luckily, none 

 entered his eyes, else there would have been trouble. 



