72 



THE ROYAL SOCIETY OF CANADA 



It is evident that 38° is about the limiting temperature to which 

 R. pipiens can be exposed for a short time without fatal result. 



The remaining experiments in which the frogs were immersed 

 in water are shown in the following table. In these experiments 

 the time taken to reach the constant maximum temperature from 

 room temperature was from 10 to 30 minutes. These experiments 

 were carried out between January 18th and 22nd, 1915. 



Expt. 



No. 



10. 



11. 



Temperature 



External 



35°C. 



28.0° 



27.5° 



26.0° 



35°-36' 



33.0° 

 33.0° 

 32.0° 



35.0° 



32.0° 



31.0° 



Internal 



35 °C. 



28.0° 



27.5° 



26.0° 



35°-36° 



33.0°-33.2° 

 33.0°-33.2° 

 32.0°-32.3° 



35.0°-35.2° 



32.0° 



31.0° 



Dura- 

 tion of 

 expo- 

 sure 



15 min. 



15 



25 

 35 

 30 



30 

 30 

 30 



45 



60 



60 



Result 



Fatal 



Not fatal 



Fatal 



Not fatal 



Fatal 



Remarks 



Unconscious when re- 

 moved from water. Heart 

 beat recommenced but 

 there was no recovery. 



Became unconscious in 

 10 min. Recovered in 5 

 min. 



Became unconscious in 

 20 min. Recovered in 

 one hour. 



Became unconscious in 

 30 min. Recovered in 

 2 min. 



No sign of life when re- 

 moved from water. Heart 

 beat recommenced, but 

 there was no recovery. 



As in expt. 5. 



As in expt. 5. 



No sign of life when re- 

 moved from water. Re- 

 covered. 



No sign of life on re- 

 moval. Muscles re- 

 sponded to stimulation. 



Some muscle tissue re- 

 sponded to elec. stimula- 

 tion. No recovery after 

 20 hours. 



On removal from water 

 examination of web of 

 foot under microscope 

 showed corpuscles mov- 

 ing very slowly in larger 



