TEMPERATURES IN TURTLES. 



441 



that observations under experimental conditions might yield 

 interesting although not exactly comparable results. The speci- 

 mens were taken directly from the lake and fastened in containers 

 in direct sunlight, one thermometer giving body readings and 

 another, in air, the environmental changes. The surface tem- 

 perature of the lake at this time was 20.5 degrees C. or 69 degrees 

 I .. and the initial temperatures of the turtle as they were taken, 

 \\a> only a few decrees less. But at the start of the experiment, 

 afti-r a la|>-r of some fifteen minutes, due to exciu-nu-nt and 

 activity in tin- containers, it had approximated the air tem- 

 perature. 



TABLE Y. 



\YhetluT or in it the same relative increase in body temporal im 

 occurs in tin- i a-e of the animals observed on the log, is of course, 

 i|iir-ti(inalilr. It was noted that the appendages were out- 

 Mtvtrlu'd as \\-ll as the neck and that after an interval of an 

 In ni r or ux.it thus exposed, as a rule, a return to the water was 

 made. .\i> ilnibt also, some slight air currents played upon the 

 body surface, thereby favoring any transpiration that mi^lit 

 ha\r luviirivil. Under experimental conditions, the operation 

 of >iu h factors to help keep the temperature down was very 

 limited. 



Tlu- average fluctuations in body temperature of five indi- 

 vidual:- an- ] ill it ted against increased environmental temperature' 

 and ^luiun in Fig. 5. It is noted there are points on the plot 

 of tin- rit\ iromnental curve which are somewhat widely displaced. 



