264 ADOLF H. SCHULTZ. 



low as 124 and no. The great excess of male abortions in the 

 early months of pregnancy, as found by Auerbach and Carvallo, 

 may find its explanation in the fact that in the statistics used by 

 them the sex of the foetuses was determined by various individ- 

 uals, who had not the necessary specialized knowledge. Early 

 in the differentiation of the external genitalia only the expert 

 can state the sex with certainty. At this time, and even later, 

 the inexperienced, misled by the size of the clitoris as well as by 

 other factors, may erroneously determine the foetus as male. 

 Fewer errors would be made if only those cases definitely male 

 were reported as such, and all the doubtful cases were designated 

 as female. Even granted that larger statistics might raise the 

 sex-ratio, the latter would never reach the high figures stated by 

 Auerbach and Carvallo and assumed by others. Just as sex- 

 ratio of mortality following birth varies according to age^ so is it 

 found to be true for pregnancy. Nothing is know r n in regard to 

 the sex-ratio during the first two months of pregnancy; however 

 that of the third month might be used hypothetically for this 

 period. The mortality of male foetuses in the third month, 

 which is about one fourth again as large as for females, is fol- 

 lowed by a mortality in the fourth to the seventh months which 

 is approximately relatively equal, for both sexes. During the 

 eighth to tenth month this relation again shows a higher mor- 

 tality for the males. The author's material from the fourth to 

 the seventh month shows a sex-ratio of 101.1. However, on 

 account of the great variability in the individual months, it is 

 quite probable that of the male and female foetuses that survive 

 the third month, the number that perish during the following 

 period up to the seventh month is relatively, not absolutely, 

 equal. 



If one proceeds to make use of the above citations and figures 

 in computing the primary sex-ratio, rough and approximately 

 average values must first be established. The following appear 

 to be most probable: 



For each 100 living born with sex ratio 105.5 

 8th-ioth month 4 still born 130 



4th-?th 9 abortions " 106.3 



o 3rd " 14 abortions " " " 125 



127 conceptions " 



