July 11, 1884.] 



SCIENCE 



37 



turtles take refuge after the first hard or plant- 

 killing frost. There they remain in the deeper 

 and warmer water, when the shallower portions 

 of the pond are coated with ice. Do they lie 

 in the mud, in these holes, in a torpid con- 

 dition ? 



Throughout the winter I have found that 

 man}* of our fish also congregate in these same 

 deep holes, and the turtles prey to a certain 

 extent upon them ; the snapping-turtles (Che- 

 lydra serpentina) occasionally catching one, 

 and the other turtles feeding upon the remains 

 of the snapper's feast. What first gave me 

 this impression was the fact, that even in mid- 

 winter, in nets set under the ice, I frequently 

 found fishes that had been partially eaten ; and, 

 as this also occurs in summer, I took it 

 for granted that the offender was the same 

 in each case. Led by this inference, I baited 

 hooks, and placed them in the deep holes 

 of a large pond, and in several in 

 stances succeeded in catchin 

 specimens of the stinking or 

 musk turtle (Ozotheca 

 odorata) and of the 

 mud-turtle (Ci- 



some six months of each year ; and, again, 

 it is certain that the species mentioned as 

 active during the winter, do also, under certain 

 conditions, regularly hibernate. The most, 

 therefore, that can be claimed from my ob- 

 servations, is, that the habit, in some spe- 

 cies, if not all, is under the control of the 

 animal, and that its exercise is optional. 



Snakes, I find, are by far the most sensitive 

 to cold of all our animals, and avoid exposure 

 to it by every available means. Certain of 

 them, when hibernating, are stiff, cold, and 

 unyielding, their condition more nearly resem- 

 bling death than that of other animals under 

 like conditions. Still we see a difference in 

 the conditions when we compare the habit as 

 exercised by different species. The water- 

 snakes hibernate quite differ- 



CHELTDRA SERPENTINA (ONE-HALF NATURAL SIZE). 



nosternum pennsylvanicum) . In the same 

 way snapping-turtles have been caught, during 

 the severest cold weather, in deep holes, and 

 about large springs that discharge their waters 

 on level ground. It would seem, therefore, 

 that, if the water remains above the freezing- 

 point, these turtles can remain in a fairly 

 active state, even though they do not find any 

 large amount of food. In such spring-holes 

 the grass remains green throughout winter ; a 

 few frogs linger in the waters ; an occasional 

 bittern haunts the spot ; pike, too, are not un- 

 usual ; and the snapper, therefore, has com- 

 pany at least, and occasionally he makes a 

 meal of some one of the hardy visitors, which, 

 like himself, brave the winter, and do not seek 

 to avoid its rigors by a protracted torpid sleep. 

 As I have not found specimens of each of 

 the aquatic and mud turtles under such cir- 

 cumstances, it may be that some of them are 

 less hardy, and do regularly hibernate for 



ently from upland snakes. The former seek 

 refuge from the cold in mud beneath water : the 

 latter burrow into dry earth. The former, when 

 disturbed, or on exposure to the atmosphere, 

 ' come to ' almost immediately : the latter may 

 be literally broken into pieces without giving 

 evidence of life. By ' water-snakes ' I mean, 

 not one or two species of Tropidonotus. that are 

 strictly aquatic, but the several garter-snakes 

 (Eutaenia), and all those that readily take to 

 the water when pursued, as distinguished from 

 the terrestrial species proper, such as the black 

 snake, adder, calico- snake, and others. In- 

 deed, I have sometimes wondered if the true 

 water-snake (Tropidonotus sipedon) really 

 hibernates at all. By dipping a foot or two 

 beneath the sand of any spring-hole, we can 

 usually find one or more of these snakes : and, 

 though somewhat sluggish in their movements, 

 the}* are not slow to swim off when released, 

 however cold the water may be. I have 



