THE USE OF SNAKES. 25 
THE PoIson FANGS. 
In the typical venomous snakes, the outer row of upper teeth 
has vanished, with the exception of fangs, more or less large, 
and set in the front part of the upper jaw. These fangs are 
either deeply grooved or hollow, and are connected by a channel 
or duct with the poison glands, which secrete the venom. The 
poison glands, with but one or two exceptions, lie one on each side 
of the head, just below and back of the eyes. These glands are 
almond-shaped, and vary in size according to the species of snake. 
In the Puff Adder they are about the size of a small almond. 
The venom is secreted by the cells composing the gland, and is 
H 
Usb 
a 
ANATOMY OF THE HEAD OF A VENOMOUS SNAKE. 
Fic. 14.—A. Duct from the poison gland, the end of which is bent upon itself and 
resting in the hole at the base of the fang into which the venom is squirted. 
B. Digastric muscle which opens the jaw. 
C. Poison gland. 
D. Point of junction of the squamosal and quadrate. 
E. Anterior temporal muscle. 
F. Posterior temporal muscle. 
H. The bifid tongue. 
I. Lower jaw in which some solid re-curved teeth are set. 
d. Trachea or windpipe. 
expelled through the duct, down the grooved or hollow fangs 
into the punctures when the snake bites. The venom is driven 
out of the glands by the construction of certain muscle fibres 
which compress the glands violently. 
THE USE OF SNAKES. 
In hot countries, insects, reptiles, batrachians, and rodents 
swarm. The snakes are the natural enemies of these creatures, 
and act the part of Nature’s agents in checking their too rapid 
