THE SNAKES 199 



is the absence, among all of the former, of any trace of 

 an external ear. Internally, the serpent's ear consists 

 of a thread-like bone and crude accessories. The ear 

 seems to be in a state of degeneracy, but an ear is unnec- 

 essary, for snakes hear with their tongues. The delicate, 

 nerve-supplied tips of this wonderfully specialized organ 

 are highly sensitive to vibrations from even slight sounds. 

 Besides, the tongue serves many purposes; vulgarly 

 speaking, it is a "feeler" and of enormous value to the 

 reptile. 



In the osteological characters of the snake's body we 

 find no marked difference from the limbless lizards. 

 While all of the snake-like lizards have traces of internal 

 limbs and the pelvic girdle, most snakes are devoid of 

 such ; but among the members of the older families, the 

 Boidce and some of the burrowing snakes, internal limbs 

 are still present as well as bones representing the pelvic 

 girdle — in fact, among some of the true snakes we find 

 better developed limbs and pelvic bones than existing 

 with some of the burrowing lizards. With the Boas 

 and Pythons, the limbs are visible externally as bony 

 spurs which are capable of vigorous movement. 



Looked at from a concise standpoint, snakes may be 

 described as the most specialized among all living rep- 

 tiles, having originated from the lizards. Aside from 

 the great modification of the jaws into an apparatus 

 to engulf large prey entire, we find the most elaborate 

 and remarkable structure pertaining to the dentition 

 among all reptiles — the poison-conducting teeth or fangs 

 of the venomous species. Hence, among creatures that 

 man has seen fit to describe as lowly and repulsive, has 

 existed for ages a perfect apparatus that man has dis- 

 covered but yesterday, and this in the shape of an instru- 

 ment of immense value to himself — the hypodermic 



