MALE-PRODUCTION IN HYDATINA 



537 



paper, with the exception of experiment 5, were performed with 

 these New Jersey rotifers. 



Table 8 shows the results of experiment 6. 



While the last three divisions of table 7 show differences of 

 the kind expected, these differences are small. Comparisons 

 based on the first three divisions of that table would indicate 

 that Euglena is about 18 times as potent in increasing male- 

 production as is oxj^gen. Or, deducting from the total effect of 

 Euglena the 1.1 per cent which a comparison of the second and 

 third divisions of the table would indicate was due to oxygen, 

 the effect of the Euglena as food would be nearly 17 times as 

 great as that of oxygen. 



A different result, however, is found in table 8. The first 

 three divisions of the table show that oxygenation increases the 

 proportion of male-producers 5.1 pel* cent, Euglena 20.2 per cent. 

 Deducting from the total effect of Euglena the fraction charge- 

 able to oxygen alone (20.2 — 5.1 = 15.1), Euglena as food is 

 nearly three times as effective as oxygen in increasing male- 

 production. 



TABLE 8 



Showing the effects of oxygen, Euglena, and creatin upon the proportion of male- 

 producers ill, a New Jersey line of the rotifer Hydatina senta 



