380 THE SNAKES OF SOUTH AFRICA. 
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 day. 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. 
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 
hours. Careful dissection showed no traces of hemorrhage. 
Some other experiments followed which showed that sometimes 
Mole snakes died after being bitten, but more usually they 
exhibited no symptoms of poisoning. 
Non-VENOMOUS SNAKES. 
The venom of the Cape Cobra is usually fatal to small snakes 
of the non-venomous species. Frogs die almost instantly. 
Toads linger a long time and often make a complete recovery. 
Mole snakes as a rule are not affected by the venom of poisonous 
snakes. If an exceptionally large dose be injected they some- 
times die. When six drops of Cobra or Puff Adder venom was 
injected under the skin on the middle part of the back of the 
snake it was generally fatal. 
