266 THE ROYAL SOCIETY OF CANADA 



springs, and are themselves subjected to temperatures below the 

 freezing-point of water. 



(5) There seems to be a slight variation in the death-temperature 

 from cold of different species of frogs, amounting to some tenths of a 

 degree Centigrade. 



(6) Frogs heated rapidly to normal room temperature from a 

 temperature just below the freezing-point of their body fluids (and 

 not itself capable of causing death) are thrown into a peculiar hyper- 

 sensitive condition, in which cessation of lung-breathing takes place 

 for long periods. 



I desire to thank Professor Swale Vincent for his continued interest 

 in this work. My thanks are also due to Miss Dickerson and Dr. 

 Hussakof of the American Museum of Natural History for assistance 

 in obtaining the southern species of frogs which I have employed. 



This work has been carried out in connection with a committee 

 of the British Association for the Advancement of Science, appointed 

 to consider "The Effect of Low Temperatures on Cold-blooded 

 Animals." 



The expenses of the research have been in large part defrayed 

 by a grant to Professor Vincent from the Government Grant Commit- 

 tee of the Royal Society of London. 



