38o THE SNAKES OF SOUTH AFRICA. 



one with its own venom. In none of these cases did any poisonous 

 S3''mptoms follow. I also allowed Puff Adders, Boomslangs, and 

 Night Adders to bite Ringhals snakes in the tail region, but in 

 no case did any of them seem the worse. 



Being desirous of knowing if the venom of the Ringhals would 

 have any poisonous effect upon non- venomous snakes I made one 

 bite a Mole snake several times, drawing blood. The Ringhals was 

 a large specimen of the black variety. No bad effects followed, 

 although I kept the Mole snake for several months afterwards. 



I once also caused a Puff Adder to bite a Cape Cobra in the 

 tail region. It gave two full bites, driving its fangs deep into 

 the flesh. Care was taken that the bite should be in the muscles 

 between the vent and the tip of the tail, as sometimes the mechani- 

 cal injury of the large fangs of a Puff Adder will cause death, if 

 the bite should be over the parts containing the vital organs. 

 The bitten snake died the following da}'. On two subsequent 

 occasions I diluted eight drops of Puff Adder venom with a little 

 pure water. Dividing this mixture into portions I injected it 

 under the skin of two Cape Cobras, each four feet in length. 

 The Cobras showed no symptoms of poisoning and continued to 

 remain in their normal condition during the six weeks they were 

 under observation. 



Non-Venomous Snakes. 



The experiments on non-venomous Mole snakes were some- 

 what contradictory. Two adult Cape Cobras bit two Mole 

 snakes, each four feet in length. The bites were full ones, 

 being in the muscles of the tail region on spots from which the 

 scales had been removed. The Mole snakes did not develop any 

 symptoms of poisoning. 



Taking two more adult Mole snakes I allowed large yellow 

 Cape Cobras to bite them effectually in the tail region. I then 

 made two small incisions and introduced some Cobra venom on 

 the point of a penknife. The Mole snakes died within fifteen 

 hours. One died in twelve hours and the other in fourteen 

 liours. Careful dissection showed no traces of haemorrhage. 

 Many other experiments followed which showed that sometimes 

 Mole snakes died after being bitten, but more usually they 

 exhibited no symptoms of poisoning. Six drops of Cobra or 

 Puff Adder venom was usually fatal to Mole snakes. 



