486 THE SNAKES OF SOUTH AFRICA. 
there any appearance of the fangs having penetrated through 
the skin, nor was there the slightest symptom of poisoning 
manifested in the animal. Many times I have been bitten on 
the bare hands by Schaapstekers, but in no case did I give the 
reptile time to get a full grip so as to work its fangs well home. 
Slight discoloration of the part bitten, and a certain amount of 
pain in the glands of the armpit supervened. However, in the 
majority of cases there was not the slightest symptom of 
poisoning. 
STARTLING RESULTS OF EXPERIMENTS. 
I allowed five newly-captured Schaapstekers (Tvimerorhinus 
rhombeatus) to bite the bared legs of five fowls. Each snake 
was permitted to take a full grip and hold on for several seconds. 
Three of the fowls showed no symptoms of poisoning. One 
became drowsy and died in about six hours. The other moped 
for a day, but recovered completely. The flesh for an inch 
around the site of the bite was a light greenish-yellow, and the 
whole leg was slightly swollen. Taking another batch of fowls, 
six in number, I caused six different Schaapstekers to bite them 
on a part of the thigh previously bared. Each snake was allowed 
to hold on for several seconds. In two of the fowls it was noticed 
that immediately under the two punctures made by the fangs 
slight discoloration occurred, showing that the fangs had really 
gone through the skin and ruptured some capillary blood-vessels. 
In both these instances the fowls died. One died in ten minutes, 
the other in seventeen minutes. 
These experiments were repeated until it was clearly proven 
to me that, should the Schaapsteker succeed in fully penetrating 
the skin, and should it be able to force a little venom through, 
its toxic effects were very powerful and rapid. The poison is 
evidently more or less akin to that of the Cobra, for no haemor- 
rhage occurred in any part of the body. This shows that the 
poisonous principle which kills in the Schaapsteker venom is a 
powerful neurotoxin. 
It is a difficult matter to collect venom direct from back- 
fanged snakes. However, I succeeded and discovered that, 
weight for weight, Schaapsteker and Boomslang venoms were 
more poisonous than those of the dreaded Cobra or Mamba. 
Here we have two species of snakes of the back-fanged 
