378 THE SNAKES OF SOUTH AFRICA. 
same species several times without any poisonous symptoms 
supervening. In three separate instances I collected six drops 
of venom from fresh Puff Adders and injected it without effect. 
Collecting a full charge of venom from an adult Puff Adder, 
I mixed it with a little water and injected it under the skin of the 
snake I had drawn it from. It produced no poisonous symptoms. 
I repeated the experiment with two other Puff Adders, with like 
results. 
Puff Adders occasionally die when bitten by snakes of other 
species such as the Cobra, Ringhals, Mamba and Boomslang. 
Extreme internal hemorrhage occurred in two bitten by a 
Boomslang. However, it is only now and then that Puff Adders 
die when bitten by other venomous snakes. I have several 
times injected Puff Adders with Cape Cobra venom, and in other 
cases allowed the reptile to inflict a full bite in the tail region. I 
have injected five drops at a time under the skin of a Puff Adder 
without poisonous effect. This means that in these cases the 
Puff Adders withstood enough Cobra venom to kill six or more 
men. 
It will thus be seen that the venom of the Puff Adder is not 
poisonous to those of its own species, or even if one be allowed 
to bite itself, or if its venom be collected and injected hypo- 
dermically into it. This would seem to indicate that the blood 
of a Puff Adder should be an antidote to its own venom, and 
others of its species. Strange to say this is not so. Collecting 
the venom from a Puff Adder I measured out three drops, and 
killing the snake, I took half an ounce of its blood and mixed the 
three drops of venom with it and allowed it to stand five minutes. 
Stirring it well, I injected it under the skin of the thigh of a fowl. 
The fowl died in four hours. Other tests ended similarly. Mixing 
the-gall of the same snake with two drops of the venom, I in- 
jected it into another fowl. The fowl died in six and a half 
hours. 
CAPE COBRAS AND RINGHALS. 
I have demonstrated by repeated experiments that the venom 
of the Cape Cobra produces inflammation of the tissues and 
eventual death in those of its own species when the venom is 
injected under the skin or when another of its own species is 
allowed to deliver a full bite. Cobras which were forced to bite 
