176 



W. C. ALLEE 



5 after the isopods had been treated with alternating solutions 

 for over two hours. The reactions of the different individuals 

 are shown by the different lines and are duly labeled in the 

 figures. No. 188 is repeated in figure 4 for the sake of com- 

 parison. Figures 3 and 4 are from work done in 1913 with N/10 

 potassium against M/5 calcium chloride and figure 5 is from 1914 

 results with both solutions 1/10 normal. 



Fig. 4 Showing antagonistic action of n/10 potassium chloride and m/5 cal- 

 cium chloride on positive rheotaxis of three isopods. For explanation see text 

 p. 175. 



Fig. 5 Showing antagonistic action of n/10 solutions of potassium and cal- 

 cium chlorides on positive rheotaxis of three isopods. For explanation see p. 

 175. 



