144 SNAKES. 



Schlegel, who carefully studied this action, observed some- 

 times as many as thirty such partial dilatations of the trunk 

 and lung between two full inspirations. 



In the large reticulated python I once saw that about 

 two feet of the body, viz. four to six feet from the head, 

 dilated with occasional and irregular inspirations, and no 

 other part. By and by slight indications of breathing were 

 observable much lower down, many feet apart from the 

 previous action, while during the whole time I was watch- 

 ing I saw not one full and entire inflation of the lungs. 

 This was on a rather chilly September afternoon, and 

 the python had partaken of a couple of ducks for dinner 

 the previous day, and it was a time when inactivity is 

 usual. In a rattlesnake, on the same day, similar partial 

 and irregular respirations were observable, this serpent 

 having caused four rats to disappear at his last night's 

 supper. 



Sometimes you can discern no indication whatever of 

 breathing for a very long time. When the reptiles are not 

 in health, when they are about to cast their skin, or when 

 in a half-torpid condition, you may observe this. 



When a snake yawns — a long and leisurely proceeding — 

 the lungs are doubtless greatly refreshed ; otherwise these 

 reptiles do not rest with their mouths open, and the 

 only possible access of outer air by the lips being through 

 the chink appropriated to the service of the tongue (and 

 which is as exactly opposite the opening of the tongue- 

 sheath as the nostrils are opposite to the glottis), they must 

 breathe almost entirely through the nose, except zuheu 

 yawning. 



