OUR ANCIENT ENEMY THE OPHIDIAN. 65 



working his jaws back to a state of repose, and gulp- 

 ing down a few breaths to make up for the time just 

 past when breathing was somewhat difficult. 



Like the batrachians, the snakes sleep all winter 

 waking up after a seven or eight months' nap under 

 the vivifying influence of spring sunshine, and with a 

 sharpened appetite for frogs, mice, and the like. At 

 this time, too, the snake discards his dull skin and 

 arrays himself in a resplendent coat of iridescent 

 colors. The skin is shed complete, inside out, and 

 scraped off by the contact with bushes, rough ground, 

 and dead leaves. 



Now the method of a snake's locomotion is as 

 curious as its habit of hibernation. "Watch one move, 

 and it is hard to tell Jiow he moves. "We may think 

 it is entirely by lateral pressure against every blade 

 of grass and every grain of sand ; but that is not all. 

 The lithe creature does something more than push 

 himself along. Every rib is employed in a measure 

 as a leg would be, and with careful observation one 

 may detect a certain undulation in wavelike intervals 

 beneath the skin, which is due to the contraction and 

 expansion of the ribs as the snake moves. Thus a 

 snake can, if he chooses, move in almost a straight 

 line and over rather slippery surfaces. 



The constricting power of some snakes is also a 



marvel. "With lightninglike rapidity the reptile will 

 6 



