224 



HELEN DEAN KING. 



TABLE VI. 

 EGGS FERTILIZED IN SOLUTIONS OF ACETIC ACID. 



In all cases the number of individuals in which it was possible 

 to ascertain sex was less than one half of that which the lots 

 contained one week after the experiments were started. In spite 

 of this great mortality, due in some cases to accidents, the results 

 are about the same as that obtained where eggs were fertilized in 

 a solution of hydrochloric acid (Table V.). In this series each 

 lot of individuals gave a percentage of females that is consid- 

 erably lower than that found in the control, and also much below 

 that which appears to be normal for the species. Curiously 

 enough the smallest percentage of females appears in the lot of 

 individuals reared from the eggs of female a which had been fer- 

 tilized in the weaker solution. This result may mean that a 

 solution of the strength employed in this instance is more favor- 

 able to the production of males, but more probably it is merely 

 a chance variation in the sex ratio. 



The results of this series of experiments are especially inter- 

 esting and suggestive when compared with those obtained in 

 other cases where eggs from the same females were fertilized 

 under very dissimilar conditions. Eggs from female a were 

 fertilized out of water with sperm from the same male used in 

 fertilizing the eggs in this series. In the one case a great excess 

 of females was produced (Table III.); in the other case the per- 

 centage of females falls much below normal. Between the two 

 extremes of the series there is a difference of 24.53 per cent. 

 Eggs from female b when subjected to the action of a salt or of 

 a sugar solution before fertilization gave in both instances 70.00 

 per cent, of females; when other eggs from this female are fertil- 



