Vol. XLI November, 1921 No. 5 



BIOLOGICAL BULLETIN 



ON THE INFLUENCE OF TEMPERATURE ON THE 



EXCRETION OF THE HIBERNATING 



FROG, RANA VIRESCENS KALM. 



H. C. VAN DER HEYDE.i 



From the department of physiology and physiological chemistry of the West 

 Virginia University Medical School, Morgantown, W. Va. 



Received for publication February 21, 1921. 



Almost all vital phenomena have been studied as to the 

 influence of temperature on their magnitude. In his excellent 

 book on 'Temperatur und Lebensvorgange," Kanitz gives a 

 summary of the work done in this field, and tries to show that 

 the R-G-T rule of van't Hoff-Cohen holds true also for the 

 reactions of organized material. In Loeb's laboratory it was 

 found by Snyder and Robertson that the heart-beat of inverte- 

 brates and of the lower vertebrate follow this rule. These obser- 

 vations have been confirmed and amplified by several authors. 

 For the mammalian heart also some investigators among them 

 Snyder tried to show that its frequency follows van't Hoff' s 

 rule. Other observers however could not agree on this point 

 and emphasized the complexity of the phenomenon, which would 

 make it improbable that this rule, which holds true for simple 

 chemical reactions, could be applied to these more complex 

 phenomena. The rhythm of breathing, the velocity of con- 

 duction in the nerve, the activity of the muscles, the geotropic 

 and phototropic movements of plants, the effect of poisons, the 

 length of life, the rate of development and growth, all have been 

 studied from this point of view, and a great diversity of opinions 

 exists as to whether the rule of van't Hoff holds true or not. 



1 Thanks are due to Mr. R. Goldberg, who made some of the total nitrogen, 

 urea and ammonia determinations for me. 



2 Aristides Kanitz, "Temperatur und Lebensvorgange," Berlin. Gebr. Born- 

 traeger, 1915. 



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