Okble 10 .--Chi- square test of the relative numbers of different types of 

 organisms attacked in tanks 1, 3, and k of Experiment I. 



Chl-square value of 5.18, with 6 degrees of freedom. 

 (Not significantly different) 



Okhle 11. — Chi-square test of the relative numbers of different type 

 of organisms attacked in tank 2, Experiment I and 

 check tank 3, Experiment II 



(T = Tank) 



Chi-square value of 4.69, with 3 degrees of freedom 

 (Not significantly different) 



16 



