190 CHARLES R. STOCKARD AND GEORGE N. PAPANICOLAOU 



ence of 37 between the number of males to 100 females in ani- 

 mals from treated-female ancestors as compared with those 

 from both male and female ancestors treated is indeed very 

 ^';reat. 



Are these differences in sex ratio a result of the direct influ- 

 ence of alcoholism upon sex determination or sex differentiation? 

 Or are they indirectly brought about by a difference between 

 the early prenatal mortality rates of the two sexes in the sev- 

 eral groups considered? Or are these merely chance differ- 

 ences? There is no doubt that chance plays a large part in the 

 make up of all sex-ratios, but to be consistent in six straight 

 cases as the six groups show can scarcely be dismissed as a 

 chance result. 



It is very peculiar that these different sex-ratios should coin- 

 cide in a direct manner with differences in the early prenatal 

 mortalities among the several groups of table 6, and thus suggests 

 that the explanation for the sex-ratio differences may be in part 

 at least along the line of the second of the above propositions. 

 After considering this probability of differences between the 

 early prenatal mortalities of males and females, we may then 

 discuss the further possibility of the direct effects of the treat- 

 ment on the sex-ratios. 



The groups having the lowest sex-ratios, female lines with 

 ratios 96.8 and 86.5, also have, as shown in tables 3 and 4, the 

 largest average litters, 2.69 and 2.66, or the lowest early pre- 

 natal mortality. The lines having a somewhat higher sex-ratio, 

 male lines with ratios 101.7 and 109.1, have correspondingly 

 somewhat higher early prenatal mortalities, as indicated by the 

 smaller average litters, 2.41 and 2.42; while the lines having 

 the highest sex-ratios, double lines with ratios 121.1 and 123.5, 

 have along with these the highest early prenatal mortalities as 

 shown by the smallest average-size litters, 2.28 and 2.37. 



This is certainly a very suggestive parallelism. And if one 

 now considers the fourth line of the table giving the total dead 

 of each sex, in every column, with one exception, it will be seen 

 that the female mortality is higher than the male. The ex- 

 ception is in the column from both parents alcoholic; here the 



