* Newman, Habits of Tortoises. 129 



swimming about on the surface, but spend much of their time 

 resting half-buried in the mud. I had an excellent opportunity 

 of observing this preparation for the winter in the case of two large 

 females that were confined within a lattice enclosure in a lagoon. 

 They buried themselves in a peculiar way — by rocking the body 

 from side to side and throwing the mud up in such a way that it 

 settled on the carapace and covered them quickly from sight. By 

 continuing this movement they sunk deeper and deeper, leaving 

 only the snout protruding from the mud. 



A few days later the water of the lagoon froze over and I could 

 still see the snouts of the tortoises, but when the ice extended to 

 the very bottom they must have withdrawn deeper into the mud. 

 It was a matter of some surprise to find both of these animals 

 alive when the ice thawed out. After a day or two, however, they 

 died and examination showed that they had suflFered from frost. 

 This, then, could not be considered as a normal case, as under 

 natural conditions the animals would be able to bury themselves 

 below the frost line. The observation shows, however, that they 

 are capable of living through the winter without the use of air or 

 water for respiration. 



Resting and Basking. — Under ordinary conditions Aspidonectes 

 basks in the open air less frequently than do other species. 

 Occasionally I have seen isolated specimens basking in company 

 with a number of Graptemys on floating objects at a safe distance 

 from shore. On my approach they have invariably been the first 

 to slide off into the water. 



This quickness to escape is facilitated by a characteristic habit 

 of turning around so as to face the water, whenever they climb 

 out upon a floating object or upon the shore. Thus no time is 

 lost in turning around when danger approaches. The same trait 

 I have observed in other parts of the country — notably in the 

 rivers of northern Illinois. Here the animals basking on the 

 somewhat precipitous river banks had their heads down so that 

 they could swim away without loss of time or equilibrium. 



Their favorite method of warming up — a process that seems to 

 be a physiologic necessity for reptiles in general — is to lie in very 

 shallow water. When seen under these conditions they are 

 always rather thinly coated with mud which they throw up by the 

 use of the rocking or careening movement previously described. 

 Sometimes the snout is protruded above the surface of the water 



