1.^2 SNAKES. 



and protruded from the mouth by the action of (certain 

 surrounding) ' muscles. In marine serpents the glottis is 

 situated very near the fore part of the mouth, and the air 

 can be inspired at the surface of the water without exposure 

 of the jaws.' 



The lungs of snakes, then, are supplied with air through 

 that moveable tube, and the ' glottis,' which is the mouth or 

 opening of what may here be called the air-tube, not to 

 venture on scientific terms, was what I had seen ' puckered 

 up,' as it appeared. 



We may briefly remind the reader that our own throats 

 contain two passages, one to the lungs, the other to the 

 stomach ; and in order that the air passage may be safely 

 guarded from the entrance of any foreign particles, there 

 are various parts, valves, and muscles which come into play 

 with the action of swallowing, each and all having technical 

 names, larynx, pharynx, glottis, epiglottis, etc., which need 

 not be here described. But in the adaptive development of 

 those wonderful creatures, snakes, the entrance or mouth 

 of the windpipe — which begins i7i their mouth — can not only 

 be closed at will, but still further to protect the passage, 

 and also to enable the reptiles to breathe during the long 

 process of swallowing, they can absolutely bring the appa- 

 ratus forward, even beyond their mouths ; and this was what 

 had so surprised me on witnessing it. 



The glottis, being the soft, membranous end or aperture, 

 was what opened and closed, expanded and contracted, by 

 that sort of puckering up and loosening again that was 

 observable, and which here was rounded, but in the higher 

 animals is a narrow, lip-like slit. 



