78 THE ROYAL SOCIETY OF CANADA 



In most of the above experiments no difference was observed 

 between the internal and external temperatures of the frog, i.e. the 

 difference did not exceed 0-l°C. The following experiments were 

 carried out in an accurate constant temperature thermostat, for the 

 use of which we wish to thank Dr. Davis of the Chemical Depart- 

 ment of this University. In the first experiment the internal tem- 

 perature of the frog was noted for some time; it took half an hour 

 to reach a constant temperature, and two hours later was 0-2°C. 

 above that of the external temperature. The frog then managed to 

 eject the thermometer from its gullet, and only the external temper- 

 ature could be noted. In subsequent experiments the frog was placed 

 in the experiment chamber unbound, and was considered to have 

 attained its maximum temperature in half an hour. Its internal 

 temperature (since the animals remained almost motionless except 

 at rare and short intervals throughout the experiments) certainly 

 did not exceed that of the air chamber by more than 0-2° or 0-3°C. 

 These experiments are of course too few to lay great stress on the 

 individual results. 



Experiment 55. April 6th, 1915. External temperature 

 25-2°C. The frog breathed fairly regularly for the first two hours. 

 The breathing became rapid after 5 hours. After 11 hours the frog 

 was unconscious and apparently dead. After 24 hours it was removed 

 and examined. It was completely dead, electrical stimulation evoking 

 no response. The muscle and heart tissues were soft. 



Experiment 56. April 7th, 1915. Similar to experiment 55 

 and with precisely similar results. (Since there was a slight, though 

 unlikely, possibility of asphyxiation producing the fatal result, a 

 frog was placed in the air-chamber at room temperature and left 

 for 24 hours, at the end of which period it was quite normal.) 



Experiment 57. April 9th, 1915. External temperature 24-3 °C. 

 After 5 hours the frog was breathing a little faster than normal; 

 after 9| hours its condition was unchanged. At the end of 24 hours 

 it was completely dead. 



Experiment 58. April 19th, 1915. External temperature 

 22-3°C. The frog commenced to breathe somewhat more rapidly 

 when first placed in the air chamber, but after 14 hours it was ap- 

 parently normal and breathing slowly; its condition was unchanged 

 after 17-5 hours. During this period the external temperature 

 varied between 22-1° and 22-3 °C. It then rose slowly to 23-0° 

 and at the end of 21-5 hours the frog was removed from the ther- 

 mostat. On removal it showed no sign of life. Examination showed 

 movement of blood in the vessels in the web of the foot, muscles 

 alive. Miscroscopic examination of a drop of blood from the anterior 



