262 



THE ROYAL SOCIETY OF CANADA 



cations that slight variations can occur in different species, to the 

 extent of a few tenths of a degree only. 



The method employed in the experiments was that previously 

 described (loc. cit., p. 120). The results are given below. The first 

 four are those previously obtained by Mr. Brownlee and myself by 

 this method. The temperatures given are for the stomach, and were 

 registered by an iron-constantan thermo-needle attached to a 

 D'Arsonval galvanometer. 



No. of 

 Expt.. 



Species 



Source Limits of 



Temperature 



Duration 



between Result 



these 



IV-13 



III 13 



IV 13 



• 5°C. 



•8° to- 



X-13 

 X-13 



X-13 



X-13 



11-13 



XI -13 

 •XI-13 



■XI 13 



I 14 

 11-14 



M4 



• 1-14 



•XI-13 

 •XI-13 



•XI-13 



•XI-13 



•IV-14 



■IV -14 



•IV-14 



00'"' 

 10°" 



Manitoba —01 

 -0-< 



R. clamilans Minnesota 



R. sphenocephala N. Carolina 



-0- 

 -0- 



10° 

 1-7° 



106° 

 -1-4° 



-1-4° 



-1-9° 



-1-45° 



-0-8° 

 -1-4° 



-0-7° 

 -II e 



•1-35° 

 1-9° 



-1-31° 

 -1-41° 

 -0-5° 

 -0-68° 

 -0-92 c 



hours 

 hours 



Recovered in 1-3 

 Recovered in 1-5 

 Did not recover. 



Tissue alive. 

 Did not recover. 



Tissues alive. 

 Recovered in 2-5 hours. 

 Did not recover. 



Tissues alive. 

 Did not recover. 



Tissues alive. 

 Did not recover. 



Tissues alive. 

 Did not recover. 



Tissues alive. 

 Recovered in 2-5 hours 

 Did not recover. 



Tissues alive. 

 Did not recover. 



Tissues alive. 

 Recovered in 1-5 hours. 

 Recovered in 20 hours 



(see below) 

 Did not recover. 



Tissues alive. 

 Did not recover. 



Tissues alive. 

 Recovered in 2 hours. 

 Did not recover. 



Tissues alive. 

 Did not recover. 



Tissues dead. 

 Did not recover. 



Tissues dead. 

 Recovered in less 



hours. 

 Did not recover. 



Tissues alive. 

 Did not recover. 



Tissues alive. 



than 2 



It will be observed that the temperature limits are much greater 

 for the Manitoban frogs than for the others. This was due to the 

 fact that the frogs used were much smaller, and consequently the 

 temperature control was not so effective. 



In the experiments there was as a rule no marked gradation of 

 body-temperature. Simultaneous observations of the skin or mouth 

 temperature were made in every case, and gave values differing only 

 a few tenths of a degree from those recorded for the stomach. 



Considering the results for R. pipiens, it is evident that no dif- 

 ferences greater than the limit of experimental error were obtained 

 for specimens from Manitoba, Minnesota, and Illinois. Considering 



