FOOD AND PARTHENOGENETIC REPRODUCTION. 



199 



Table V. 



generations, but there was a slight decrease in the difference 

 between the number of young daughter-females produced by 

 the two races. The A race during this series of observations 

 produced an average of 9.19 daughter-females while the B race 

 produced 10.06. A complete record of the results of this obser- 

 vation is given in Table VI. 



Table VI. 



The parthenogenetic reproduction of the parallel races was 

 continued over the summer of 1921 without any further obser- 

 vations. The usual care was employed in their feeding. About 

 the middle of August a wild race, C, was introduced. The 

 seventh series of observations was begun with the 169th genera- 

 tion of the A and B races and the 10th of the wild race C. Con- 

 siderable variation was found in the number of young produced 

 by successive generations of each race. The difference, however, 

 in the number of young of the B race as compared to the numbers 



