roller: respiratory responses in grasshoppers. 



215 



fresh air and atmospheric pressure for about fourteen hours, 

 the respiratory movements again appear. It was surprising 

 to see that in a few hours the heart was beating forcibly, 

 long before there were any indications of life in any other 

 parts of the body. They had been exposed twenty-four hours 

 to atmospheric air and then were again subjected to 250 pounds 

 pressure, but the respiration now ceased in about eighteen 

 hours, and revived in about half an hour, when removed from 

 the high pressure to that of atmospheric air. For the third 

 time they were exposed to about 250 pounds pressure ; the 

 decapitated stopped breathing at once, the normal within 

 twenty-four hours. The latter revived in half an hour in 

 fresh air, and then, for the fourth time, exposed to the high 

 pressure, under which respiratory movements soon ceased 

 and did not return in fresh air. 



It had been ascertained that normal grasshoppers can live 

 about four days in the laboratory without food. In these ex- 

 periments, the grasshoppers lived eight days without food. 

 The respiratory movements continued half of that time under 

 an average tension of 200 pounds, or thirteen atmospheres. 



Table I. 



