2 CHARLES G. ROGERS AND ELSIE M. LEWIS. 



forward this work, and while it does not cover as wide a range of 

 forms as we would wish, it does, we believe, give an indication 

 of what we may expect to find in a more comprehensive survey. 

 In this study forms were selected from as widely separated animal 

 groups as possible, fairly wide ranges of temperature were covered, 

 and the changes of temperatures were made both slowly and 



suddenly. 



LITERATURE. 



A table was compiled from the data obtained from various 

 reports, which though brief indicates that in most cases the in- 

 vestigators made use of mercurial thermometers. Many make 

 no statements of the means employed or of the ranges of temper- 

 ature to which the animals were subjected. Dutrochet 1 intro- 

 duced thermoelectric methods in the determination of the 

 temperature of single bees and colonies, though the more recent 

 work of Phillips and Demuth 2 is more comprehensive. The 

 latter authors used a method sensitive to a difference of tem- 

 perature of 0.09 F., and found that the bees in a temperature 

 below 57 F. tend to form clusters and to raise their temperature 

 decidedly above that of the air, but between 57 and 69 the 

 temperature of the hive follows that of the air. Work very 

 similar to this has been done upon plants. John H. Ehlers 3 

 quotes various reports which gave the temperatures of leaves as 

 high as 1 6 above the shade temperature of the air. In his own 

 work Ehlers used a potentiometer method which enabled him 

 to neglect a number of outside factors in his thermo-couple 

 determinations, and obtained in the pine leaf temperatures 2 

 to 10 above the shade temperature of the air. 



Table I., compiled from various sources, gives an idea of the 

 diversity of results obtained by different observers, and the 

 incompleteness of the data available. For example we find in 

 regard to carp alone the following reports: 



Hunter 4 carp 1.9 to 3.5 above surrounding water 



Buniva " 3.0 



Desprets " 0.86 



1 Dutrochet, Ann. d'Hist. Nat., 2, Zool. 13, p. 5. 



" Phillips and Demuth, Bull. U. S. Dept. Agriculture, No. 93, 



3 Ehlers, John H., American Journal of Botany, 2, 1915, pp. 32-70. 



4 Reported by Davy, Ann. de Phys. et de Chem., XXXIII., 1826, p. 180. 



