290 
LIFE, IN IIS HIGHER FORMS. 
has observed that the larynx is at such a- time protruded 
as much as a quarter of an inch beyond the edge of the 
dilated lower jaw.* 
Most Serpents master their prey by open violence ; and 
the large species of the tropics embrace it in repeated coils 
of thoir bodies, which are then contracted with great mus- 
cular force, so as to crush and compress their victim to 
death. But other kinds are furnished with a more securely 
fatal power, in the presence of two long, hooked, tubular 
teeth in the upper jaws. These teeth, or fangs, are open 
at each extremity, and the base communicates with a 
vesicle, which is a reservoir of powerful poison, secreted by 
glands spread over the cheeks. When a Rattlesnake or a 
Viper makes its attack, it commonly elevates the head and 
draws it somewhat back] then with lightning-rapidity it 
strikes forward, piercing its enemy with the projecting 
fangs; at the same instant the poison-bag, which has been 
just filled by the secretion, poured forth under the excite- 
ment of rage, is compressed by its proper muscles, and the 
deadly fluid is injected through the tubular tooth into the 
wound. 
In the harmless Snakes (or rather those which are not 
poisonous), each of the upper and under jaws is set with a 
number of small, but very sharp teeth, pointing backwards; 
the palate is also armed with two similar rows, so that there 
are six lines of teeth in the mouth. Owing to the loose 
jointing of the bones before mentioned, the two sides of the 
head are capable of being moved to and fro separately, with 
a sort of see-sawing action. When the teeth have been 
struck into the victim, this alternate advance of the sides 
"Zool. Journal" ii. 
