434 FRANCIS M. BALDWIN. 



manders) but concluded that neither of these forms possessed 

 mechanisms for either heat production or heat loss. 



Experimental. -Turtles were collected in the vicinity of Lake- 

 side Laboratory, Lake Okoboji, Iowa. The painted variety was 

 unusually abundant in July and August in the shallow cove at 

 Miller's Bay. The snappers were comparatively rare and could 

 not be obtained iir considerable numbers. Most of these were 



FIG. i. Diagram of relationships of the apparatus used in cooling experiments. 

 The animals were made fast by clamp in the smaller container surrounded by 

 water, and this subjected to an ice bath. Temperatures were read from the three 

 thermometers shown. 



taken from Hottes' and Marble Lakes, west of Spirit Lake, 

 while others were found along the shores of Little Sioux river 

 and in the neighborhood of Hanging Bog. Suitable specimens 

 of various sizes were placed in a live box as caught, and from 

 there were taken into the laboratory as needed. 



Individuals were weighed and mounted in such a way that 

 their temperature changes might be recorded. Those placed in 

 air as a surrounding medium were fixed to a board by heavy 

 rubber bands slipped about the carapace and plastron and 

 spaced so that the animal was unable to release itself by kicking. 



