210 



W. C. ALLEE AND SHIRO TASHIRO 



carbon dioxide and was less susceptible to potassium cyanide 

 than the control individual. In other words the calcium chlo- 

 ride (0.16 mol.) decidedly decreased the rate of metabolism of 

 the isopods and also reduced their tendency to give a positive 

 rheotactic reaction. 



TABLE 3 



Showing the quantitative daily determination of the carbon dioxide output of 

 isopods Nos. 102 and 12. Isopod No. 12 was tested quantitatively for carbon 

 dioxide production in the biometer; isopod No. 102, in a new apparatus especially 

 devised for quantitative work. Column 3 gives the capacity of the respiratory 

 chamber; column 4 shows the number of cc. of respired air which first gave the 

 precipitate of BaCO; column 5, the amount of CO 2 given by the isopod in ten 

 minutes, for method of calculation see page 203. 



* Determination in some doubt due to lack of facilities for running a duplicate 

 determination. 



t No determination because of lack of carbon dioxide free air which is required 

 n preparing the apparatus for a determination. 



THE RELATION BETWEEN DAILY VARIATION IN CARBON DIOXIDE 

 PRODUCTION AND THE RHEOTACTIC REACTION 



It has been observed that the rheotactic reaction of isopods 

 varied to a considerable degree even when the animals were 

 kept under approximately identical external conditions. (Allee, 



