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KANSAS UNIVERSITY SCIENCE BULLETIN. 



The Effect of Gradually Increased Pressures. 



Normal, decapitated and deviscerated grasshoppers were 

 first subjected to a pressure of 100 pounds. The pressure 

 was daily gradually increased until it reached 275 pounds. 



Table II shows the pressure in pounds and time during 

 which the animals were subjected to it. 



Table II. 



In animals that had the viscera and tracheal tubes re- 

 moved, the respiration continued after an exposure to grad- 

 ually increased pressure for about sixty hours, while the 

 normal animals breathed about twelve hours longer and did 

 not again revive in fresh air. The animals exhibited no 

 spasms before they were removed from the pressure, and 

 post-mortems showed that the viscera and tracheal tubes had 

 been removed. 



Table III. 



Table III shows the mean results of experiments pursued 

 \\'n\\ normal, decapitated and deviscerated immature forms 

 suddenly exposed to about 275 pounds pres-sure, or fourteen at- 

 mospheres. After an exposure for fifteen hoprs to 275 pounds 

 pressure the animals were removed to that of atmospheric. 

 The deviscerated that had the abdominal nerve cord directly 



