THE RELATION OF THE BODY TEMPERATURE OF 



THE EARTHWORM TO THAT OF ITS 



ENVIRONMENT. 



CHARLES G. ROGERS AND ELSIE M. LEWIS. 1 



In a paper by one of us upon the "Temperature Coefficient of 

 the Rate of Heart Beat in Certain Living Animals" 2 the assump- 

 tion was made that the temperature of the living animal (worm 

 or fish-embryo) under observation corresponded very closely 

 to that of the water surrounding it. The same assumption has 

 been made by other workers in this field, e. g., Snyder 3 in his 

 work upon the isolated heart of the Pacific terrapin assumed that 

 the temperature of the more or less bulky heart muscle of the 

 terrapin was conditioned by the temperature of the solution in 

 which it was placed. Robertson 4 also in his work upon Cerio- 

 daphnia assumed that the temperature of the water definitely 

 represented the temperature of the tissues with w r hich he was 

 particularly concerned. Even more recently Loeb and Ewald 5 

 make use of the same assumption. 



There are to be found in the literature of physiology state- 

 ments concerning the body temperatures of the so-called cold- 

 blooded animals, and an examination of the data offered reveals 

 the fact that the various investigators who have taken the trouble 

 to make any examination of the actual conditions find that the 

 temperatures of the animals studied vary considerably from the 

 temperatures of the surroundings. It is also true that many 



1 From the Department of Zoology, Oberlin College. 



2 Rogers, Charles G., "Studies upon the Temperature Coefficient of the Rate 

 of Heart Beat in Certain Living Animals," American Journal of Physiology, 1911, 

 Vol. 28, No. II., pages 81-93. 



3 Snyder, C. D., "On the Influence of Temperature Upon Cardiac Contraction 

 and Its Relation to Influence of Temperature upon Chemical Reaction Velocity," 

 University of California Publications, Physiology, Vol. 2, No. 15, 1905. 



4 Robertson, T. B., "Note on the Influence of Temperature Upon the Rate of 

 the Heart Beat in a Crustacean (Ceriodaphnia)," BIOLOGICAL BULLETIN, 1906, 

 Vol. X., No. 5, pp. 242-248. 



6 Loeb, Jacques and Ewald, W. F., "Die Frequenz der Herztatigkeit als eindeutige 

 Funktion der Temperatur," Biochemische Zeilschrift, 1913, Bd. 58, H 3, 177-185. 



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