POISON APPARATUS OF VENOMOUS SNAKES 67 
important is the anterior temporal,’ which arises from behind the orbit and 
from the upper two-thirds of the firm fascia of the poison gland. Its fibers 
run backwards over the gland and descend between it and the middle tem- 
poral muscle. In this course the fibers lie posteriorly to the suspensory 
ligament, and the outer ones, as they fold about the anterior end of the gland, 
lie in contact with the prolongation of the external lateral articular ligament 
upon the glandular body. Finally, the muscle winds around the commissure 
of the lips, and is inserted into the mandible some distance in front of the 
angle of the lips. ‘The middle and posterior temporal muscles arise chiefly 
from the temporal fossa and are inserted, one behind the other, into the 
lower jaw. Their fibers descend nearly vertically and their obvious func- 
tion is to close the jaw. ‘The function of the anterior temporal muscle is 
apparently twofold — to exert the pressure upon the poison gland and to aid 
in shutting the mouth in the meanwhile. 
The poison gland of Crotalus occupies the side of the head, behind the eye 
and beneath the anterior temporal muscle. Its posterior end extends three 
or four lines beyond the commissure of the lips, while the anterior extremity 
reaches below and just behind the eye. Thus situated, the gland is in rela- 
tion with the bony surface behind the eye, with the middle temporal muscle, 
with nerves which emerge under the suspensory ligament, and with the 
anterior temporal muscle above and behind where that muscle descends to 
its insertion. Beneath, the gland is in contact with the external pterygoid 
muscle, with whose aponeurosis it has peculiar relations. The portion of 
the gland below the anterior temporal muscle and above the line of the lip 
is in direct contact with the skin, which is here loosely connected with the 
areolar tissue. 
The ligaments of the poison gland are firmly connected with the tough, 
fibrous capsule of the gland, and are really in continuation of the latter. 
Anteriorly the ligament gradually tapers thin and runs forwards with the 
duct, constituting a part of its thickness. Posteriorly there is one ligament 
which attaches firmly upon the fascia of the temporal muscles. Another 
strong ligament is found to extend from the capsule of the gland to the bony 
surface beneath the gland. A third attachment of the gland is by means of 
a fascia which forms a strong expansion upon the external pterygoid muscle 
and then runs off laterally, to be inserted in the outer capsule of the gland. 
THE BITE. 
The mechanism of the bite has been studied most exactly and exhaustively 
by Weir Mitchell, who made observations on the rattlesnakes. The snake 
prepares itself for striking by raising the head a little above the rest of the 
body, but not, usually, more than 3 or 4 inches, even in large snakes. The 
neck and upper end of the trunk are not thrown into complete circle, but 
lie in two or three abrupt curves across the mass of the coiled body. The 
1M. temporalis anterior of Mitchell may be identical with M. masseter of authors, and his middle 
temporal muscle with M. temporalis anterior of authors. 
