49 



Experiment 6. On seven magpies, aged from four to eight 

 days, I put a ligature around the trachea, and opened widely 

 the thoraco-abdominal cavity. 



Nos. 

 1, 



2. 

 3, 

 4, 



5, 

 6, 

 7, 

 8, 

 9, 

 10, 



11, 



TABLE IV. 

 Temperature of the animals. 



36 Cent., (about 97 Fahr. 



36 

 32 

 31* 



26 

 26 



22 

 20 

 20 

 18 

 10 



97 

 97 

 90 

 79 



79 

 72 

 68 

 68 

 65 

 65 



Duration 

 of life. 



20' 



28 $ 



26 

 39 

 12 



58 



65 



87 



82 



103 



Mean 

 duration. 



24 ' 



50 



72 

 76 



92 



Experiment 7. On other magpies I made the same experi- 

 ment, but without opening the thoraco-abdominal cavity, so that 

 asphyxia was much more complete. 



TABLE VII. 

 Nos. Temperature of the animals. Duration of life. 



1, 35 Cent., (95 Fahr.) 8' 



2, 30 86 15 



3, 24 76 27 



4, 19 67 39 



I have obtained nearly the same results from experiments 

 upon many sparrow-hawks, ravens and jays. 



All these facts show how considerable is the influence of the 

 temperature of certain young animals and birds on the duration 

 of their life when they are asphyxiated. 



II. Differences in the length of the resistance to asphyxia ac- 

 cording to the species of animals. 



In order to discover what is the influence of the species, I made 

 the following experiment. I tied the trachea on twenty-two ani- 

 mals belonging to eleven species, all of which were aged about 

 four or five days. Their temperature had been cooled and they 

 were all at about 26 Cent., (79 Fahr.) The temperature of 

 the air was 19 Cent. (67 Fahr.) 



5 



