228 



HELEN DEAN KING. 



ized at the extreme temperatures is only 2.78 per cent., however, 

 so it is evident that the temperature at which the solution acted 

 had very little, if any, influence on the results. 



No evidence regarding the influence of temperature on the 

 determination of sex in Bnfo is given by the results of these 

 experiments, and their chief interest lies in the fact that they 

 accord so well with the results of the other investigations in which 

 eggs were fertilized in acid solutions. If we consider the series 

 as a whole and disregard the possible influence of temperature 

 on the results, it is found that in the total of 177 individuals in 

 which sex was ascertained only 58, or 32.76 per cent, are females. 

 This is 18.65 per cent, lower than the percentage of females in 

 the control lot and 7.05 per cent, less than the percentage of 

 females obtained in the former series of experiments where eggs 

 were fertilized in acid solutions at room temperature (Table VI.). 



The results of the experiments in which eggs were fertilized 

 in solutions of NaOH that were kept at different temperatures 

 during the period that the solutions acted are shown in Table IX. 



TABLE IX. 



EGGS FERTILIZED IN ALKALINE SOLUTIONS AT DIFFERENT TEMPERATURES. 



In this series also the sex ratios obtained indicate that the 

 temperature at which the solutions acted has no appreciable 

 influence on the results, although here, as in the acid series, a 

 slightly lower percentage of females was obtained where the eggs 

 had been fertilized at the highest temperature. 



Both lots of eggs that were fertilized at the extremes of tem- 

 perature used gave a percentage of females slightly below that 

 of the control and some 8 per cent, lower than that in the lot 

 where the eggs had been fertilized at room temperature. In 

 the latter case the relatively high percentage of females cannot be 

 considered as significant, as it is balanced by the low percentages 



