BODY TEMPERATURE OF CERTAIN COLD-BLOODED ANIMALS. 7 



irritation furnishes a possible source of error, especially in the 

 work upon the clam, but as no sign of increased heat production 

 was observed it may be safely inferred that this could not be of 

 any such amount as seriously to affect the results obtained. In 

 the case of the earthworm and the salamanders there was so little 

 disturbance or irritation that it seems hardly necessary even to 

 suggest the possibility of error. 



DISCUSSION OF EXPERIMENTS. 



In this discussion of the results of the experiments upon the 

 different forms certain details of procedure are included so as to 

 make clear just what was done in each series of operations. While 

 the general method is the same throughout there were certain 

 minor differences in the manner of handling made necessary 

 by the differences in structure of the animals used. 



The results of the investigation have been summarized in the 

 form of a series of tables showing the range of temperatures em- 

 ployed and the temperature relations found to exist between the 

 animal and its environment. In these tables it has been thought 

 wise to omit all except the last two or three observations made at 

 any given temperature. It will be noted that we have not in- 

 dicated the time elapsed between placing the animal under a 

 given set of temperature conditions and the recording of the final 

 result. This information, while perhaps interesting, does not 

 appeal to us as being of fundamental value in the present study. 

 In general it may be stated that in the case of the worms from 

 one to three minutes was allowed for adjustment to the tem- 

 perature of the surrounding water; in the case of the larger forms 

 a longer period was required. From one half to three quarters 

 of an hour was required for the adjustment to take place, and 

 frequently a still longer time was allowed. 



Experiments upon the Earthworm. Following the methods 

 employed in the previous work the worms were kept in the cellar 

 or brought into the laboratory as needed. The junction of the 

 thermo-couple, encased in a glass tube of small diameter was 

 inserted in the mouth of the worm and gently passed down into 

 the stomach intestine. The worm was then placed in the water 

 of the thermostat and brought to within about an inch of the 



