XXIV INTRODUCTION. 
gland at the side of the skull behind the eye. This gland is hollow, and 
contains the venom it secretes. Venom glands vary considerably in size 
and position; they extend back upon the neck in certain Conocerese. Com- 
pression by means of the muscles upon the gland forces its contents through 
the duct and tooth. This compression is entirely independent of opening 
the mouth or erecting the fangs. At the will of the serpent the venom 
may or may not be delivered with the bite. As if the creature was 
economical, and did not wish to waste its supply, it is frequently the case 
that it strikes one or more times without using the poison, and is able to 
strike a more effective blow when more thoroughly exasperated. If an 
angry snake is held up by the neck, and its mouth kept open, it will raise 
and lower the fangs from time to time, and occasionally spurt the venom 
through them with considerable force. Usually on being disturbed and 
unable to retreat, the snake throws himself into an attitude of defence by 
coiling his body so that the upper half can be readily straightened in the 
act of striking. A Rattlesnake will place the tail in the coil with the rattle 
directed upward. Very angry individuals strike whether coiled or not. 
They do not jump; the hinder part of the body remains in position, and 
none of our serpents are in the habit of reaching more than half of their 
length. If a stroke is successful, and the fangs enter the flesh of the victim, 
a backward pull throws the weight of the body on the fangs, tending to 
make free a space in front of them for the introduction of the venom. A 
blow is sometimes given when the fangs are not erected, sometimes with 
the mouth wide open, and sometimes, apparently, with the jaws closed, 
the fangs passing on the outside of the lower jaw which then serves as a 
lever with which to disengage them. After wounding it fatally, the snake 
watches the prey very intently until the venom has produced the desired 
effect and the victim falls, when it appears as if an estimate of the size was 
made with chin and tongue by passing from one end to the other of the body 
before the attempt to swallow begins at its nose. This intent gazing at 
squirrels, birds, ete., in their dying agonies, has given rise to the errone- 
ous ideas concerning fascination. All there is of fascination or charming 
is to be accounted for by the fact just mentioned, together with the quiet, 
almost imperceptible motion of the snake and the recklessness and terror- 
ism of the prey. Venom hastens decomposition, and thus renders digestion 
more rapid, 
