SEX-INCIDENCE IN ABORTIONS. 191 



changes resulting from locality, from age, nutrition, and health of the mother. 

 Sormani (1883) reported that in Italy the sex-ratio of births in urban districts was 

 104.9 and in rural districts 107.0. Nichols, in contrast to this, states that in Paris 

 the sex-ratio of new-born was 103.7 and in the remainder of France 104.3; while 

 in Paris the mortality in utero was 7.7 per cent of births, in other parts of France 

 only 4.4 per cent. In regard to the alleged influence exerted by the age of the 

 mother on the sex-ratio of her children, the finding of Dempsey (1919) may serve 

 as proof that this influence does not concern the primary sex-ratio. This author 

 finds that still-births in women of 30 years of age and over were more than four 

 times as numerous as in women under 30. 



To briefly sum up the results of this study, the author believes he has succeeded 

 in correcting two errors frequently found in the literature: 



First, that the relation of the sexes at conception does not, as frequently 

 stated, show an extremely high preponderance of males, but a surplus of 10 per 

 cent at most. 



Second, that a great number of factors claimed to influence the sex-ratio at 

 conception, if playing any role at all, are only sex-eliminating during intra- 

 uterine life and have no effect upon sex determination. 



Further results of interest are the marked fluctuations in the sex-incidence 

 of abortions and still-births in different periods of development and also the great 

 changes in the death-rate during intrauterine life. These facts may serve as a help- 

 ful guide in the search for the cause of the greater mortality among male fetuses. 2 



1 Schenk (1898) asserts that diabetic mothers bear more female than male children. 

 1 This is not restricted to man, but has been found alao for the rat. (King, 1921.) 



