206 



W. C. ALLEE AND SHIRO TASHIRO 



Allee has conducted a series of tests to find whether or not 

 Child's cyanide resistance method would apply to isopods and 

 has found decided evidence that the application is possible. 

 (Allee, '14.) As a final check upon this work we repeated with 

 isopods the tests of the relation between carbon dioxide produc- 

 tion and cyanide resistance that had been made earlier for 

 Planaria. 



The detailed method of procedure was as follows: Two 

 easily distinguished isopods of equal size, whose rheotactic reac- 

 tion had been previously tested by Allee, were placed in the 

 Biometer by Tashiro and the relative speed of carbon dioxide 

 output was determined. Immediately upon the removal of the 



TABLE 1 



Showing the relation between the rheotactic reaction, carbon dioxide production 

 and resistance to 0.001 mol. potassium cyanide. The carbon dioxide output was 

 compared in the biometer and the total reactions of two animals thus compared 

 are shown in each horizontal division of the table. 



* See discussion, page 207. 



