Our Natural Enemies. 187 
this explains the stony stare, so disagreeable to many, that 
all snakes have. 
The skeleton of snakes is so arranged as to allow the 
greatest freedom and flexibility. Numerous pieces of bone, 
hollow in front and convex behind, make up the long taper- 
ing backbone, which literally works on a ball-and-socket 
plan. Articular facets, that lock into each other, are found 
upon the processes of the vertebrx, and these strengthen 
and give to the backbone a greater degree of flexibility. A 
more remarkable arrangement, however, is found in the 
head, which enables the snake to prey upon animals that are 
larger than itself. The jaws seem a combination of elastic 
springs, having no gauge to their tension, the quadrate bones 
connecting the lower jaw with the skull being movable, 
thus allowing that enormous gape with which all are famil- 
iar who have seen a snake swallow its prey. Besides this, 
the bones of the jaw itself and palate are more or less mova- 
ble, also tending to the larger distention of the throat. 
As snakes do not tear or mutilate their prey, their teeth 
are not set in sockets, but serve merely to poison and stu- 
pefy the prey, or to prevent its escape, acting as hooks by 
which the body is hauled over the victim. The bones of 
the lower jaw, as we have seen, are not fastened closely to 
each other; so in swallowing prey the teeth on one side are 
advanced, and then those on the other side, and so on until 
the victim is hauled, hand over hand, as it were, into the 
snake’s throat. 
Poisonous snakes, such as the rattlers, have two long, sharp 
fangs, each compressed and bent up, and forming a hollow 
tube, open at both ends. The upper portion of the hollow 
fang is fastened to a bone in the cheek, which moves with 
ease, so that, when not in use, the fangs can be packed away 
until needed. 
All animals, man included, have doubtless in their saliva 
a deadly poison, though in the latter it is extremely diluted, 
and essential only to the digestion of food. In poisonous 
