478 



DAVID D. WHITNEY 



TABLE 5— Concluded 



* Average at end. 



of the vials and thus render the available food supply scarce for 

 the rotifers when they were added at the end of twenty-four 

 hours. Three days after the rotifers were added about fifty 

 young females were isolated in watch-glasses and the sex of their 

 offspring recorded. 



In many of the experiments the Chlamydomonas in the sun- 

 light had so spent themselves at the end of four days that no 

 more free oxygen was found in the culture water than was found 



