178 



STUDIES ON PATHOLOGIC OVA. 



had in 1881 a sex-ratio of 143.7 for the aborigines, and one of 118.6 for the popula- 

 tion of foreign descent. 



TABLE A. Number of females per 1,000 males. 

 (From Rauber.) 



TABLE B. Changes in sex-ratio with advancing age. 

 (From Prinzing.) 



Table A, taken from Rauber (1900), represents the number of females to 

 every 1,000 males in some of the European countries. As will be noted, the excess 

 of females increases with age. This is still more clearly shown in table B, from 

 Prinzing (1905), taken from the census of 1900 in Germany. Inasmuch as in 

 Europe sex-ratio at birth favors males, its subsequent decrease must be the result 

 of a greater mortality among the latter, and also, in some countries, of a greater 

 emigration of males. The unequal mortality is shown in table C, from Ploss (1887). 



The sex-ratio of mortality may differ with age and under various conditions 

 of life. For example, between the ages of 25 and 40 years (according to Knopfel, 

 1907) in rural districts it is below, while among urban population it is above 100. 

 A difference in the comparative death-rate of the sexes in city and rural populations 

 is shown by table D (Baker, 1910, compiled from the United States census of 1900) 

 to exist throughout life, but to vary at different ages. 



TABLE C. Sex-ratio of mortality in European countries. 

 (From Ploss.) 



TABLE D. Excess of male death-rate (per 1,000 popula- 

 tion) over female death-rate. (From Baker.) 



Bell (1918), in his studies on the Hyde genealogy, found that during the years 

 covering the child-bearing period the death-rate was greater among females than 

 among males. His conclusions were based, however, upon comparatively small 

 statistics. In opposition to this we have the more reliable conclusion of Willcox 

 (1904) that, according to the life tables of several entire countries, the death-rate 

 of women between 20 and 30 years of age (a period during which probably four- 

 fifths of the child-births occur) was less than that of males of the same age. 



