Il8 ECOLOGY AND LIFE HISTORY OF THE COMMON FROG 



Imagine an industrial society of poikilotherms, say frogs. On a 

 cold day, a factory would scarcely work at all. On a warm morning, 

 crowds of energetic frogs would surge in and set to work with a will. 

 The management would be hard pressed to provide enough materials 

 from stock, or fmd food for the canteen. Telephone orders would 

 help, for the frog drivers of vehicles would be able to rush supplies 

 along safely, because their co-ordination of hand and eye would be 

 much increased. The newspapers, of course, would not contain 

 complaints about the inaccuracy of weather forecasts. Instead, 

 indignant protests would be made that the meteorological services 

 were not able to predict the number of work units in the dayhght 

 hours for more than a few days ahead, and even then were often 

 wrong. Clocks, presumably, would have temperature-sensitive 

 devices in them, instead of compensating arrangements to annul the 

 effects of temperature, as we have in ours. 



Now, what do we really mean when we say that, in frogs, croaking, 

 migration or spawning goes on more in warm weather than in cold? 

 Do we mean that one of these functions goes on faster than the others 

 in the animal? This would be scientific news. So, undoubtedly, would 

 be the discovery that some function went on at the same speed, what- 

 ever the temperature. But the mere observation that one function 

 goes on more quickly at high temperatures than at low ones is not 

 news — what else can we expect? 



In the study of migration above, a temperature effect was reported. 

 I doubt very much if this is anything more than the result of the 

 general "porkilothermous effect," and is no more a "stimulus" to 

 migration than raised temperature is a stimulus to digestion. 



REFERENCES 



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 Blanchard, F. N. (1930) Amer. Nat., 64, 154-67. 

 BoGERT, C. M. (1958) Folkways Record Album, FX6166 (New York). 

 BouLENGER, G. A. (1897) The Tailless Batracians of Europe (Roy. Society, 



London). 

 BouLENGER, G. A. (1912) Proc. zool. Soc. Land., 19-22. 

 Breder, C. M., Breder, R. B. and Rjedmond, A. C. (1927) Zoologica N.Y., 



9, 201-29. 

 BuDGETT, H. M. (1933) Hunting by Scent (Eyre & Spottiswoode, London). 

 Chapman, B. M. and Chapman, R. F. (1958) J. Anim. Ecol. 27, No. 2, 265-86. 

 COTT, H. B. (1936) Proc. zool. Soc. Lond., 111-33. 



