440 



FRANCIS M. BALDWIN. 



A similar series of experiments was performed on four speci- 

 mens (C, B, N and 0) on the following day and the average 

 figures of these contribute to the plot, Fig. 4. The body tem- 



11 12 1 2 



FIG. 4. Plot showing the average body temperature drop from four snapping 

 turtles correlated with a slow environmental drop. 



perature curve shows a comparable drop with that of the environ- 

 ment during the first hour and a half but is checked at about 

 40 degrees. 



Body Temperature Fluctuations on Warming. Two procedures 

 were used in these experiments. On warm days with bright 

 sunlight the animals were placed in containers either in air or 

 in slight amount of water and put directly into the warm rays 

 of the sun. In other cases the temperature of the containers 

 was slowly raised by use of an alcohol lamp through a copper 

 conducting unit. The results seemed not to differ greatly in 

 either procedure. As a rule it was found that the animals could 

 withstand gradual increase in temperature in air better than in 

 water. This was due in part, no doubt, to slight though appre- 

 ciable transpiration afforded in the former condition. As illus- 

 trative of the reactions of the painted variety to gradual increase 

 in temperature, data from specimen / are given in Table Y. 

 This particular experiment together with others was carried out 

 on an unusually favorable day, August 6. It was noted that 

 hundreds of turtles were basking in the afternoon sun on old 

 logs in the cove north of the laboratory, and it was thought 



