140 THE SNAKES OF SOUTH AFRICA. 
moreover, under the microscope, a sticky, colourless fluid, identical 
with that found in the sheath, was observed in the structure of 
the glands, and was pressed out upon the microscopical slide with 
the tip of a lancet. Small pieces of these glands were cut up and 
inserted under the skin of rabbits, and slight pressure applied 
for an instant. Within fifteen minutes the rabbits were dead. 
Fic. 59.—Life-sized head of a Boomslang, showing the situation of the fangs. The gland lies 
above and behind. It is coloured black. The venom oozes from its base through a hole 
in the jawbone into the fang capsule or sheath, and is forced down the grooves in the 
fangs. 
This is a type of the Back-fanged Division of Snakes. 
One was stricken with complete paralysis within five minutes of 
the insertion of the fragment of gland. 
BOOMSLANGS ARE HIGHLY VENOMOUS. 
These and other experiments, mentioned in detail a few pages 
further on, conclusively prove these glands to be capable of 
secreting a very virulent venom, and that the glands produce the 
glairy sticky fluid within the sheaths enveloping the fangs. The 
