SEX. 319 



pestilences, and plagues, and the consequent extraor- 

 dinary rapidity with which population recovers it- 

 self in those countries where the plague, the marsh- 

 fever, or famines, which cause many of these epidem- 

 ics, have made havoc." * 



These influences have been considered in the chap- 

 ter on " Fecundity," but they are of particular inter- 

 est among the causes that determine the proportion of 

 the sexes. 



Dr. H. B. Baker has shown that the influence of 

 the War of the Eevolution and the War of 1812 are 

 indicated in the statistics of Michigan as late as 1870, 

 as well as the influence of the war of 1861-'65, a and it 

 appears that the diminished birth-rate during these 

 wars was accompanied by an increased proportion of 

 male births. 



It has been stated that " certain observations made 

 by Yillerme, of Paris, and by Dr. Emerson, of Phila- 

 delphia, go to show that certain causes, as great heat 

 of summer, overworking and underfeeding, prevalence 

 of epidemics, illegitimacy, in short, whatever tends to 

 depress the physical and moral powers, tends also to 

 diminish fecundity, and at the same time to reduce 

 the excess of male births ; that these causes may oper- 

 ate so as even to produce an excess of females." " 



Dr. John Stockton-Hough has also made the state- 

 ment that, " under ordinary circumstances, the greater 



1 Walford's "Insurance Cyclopaedia," vol. iii., p. 189. 



2 "Statistics of Michigan," 1870, pp. xix.-xxi. (See also " United 

 States Census," Mortality, 1860, p. 520.) 



8 "Registration Report of Kentucky," 1853, p. 119; as quoted in 

 Michigan "Fourth Registration Report," 1870, p. 79. 



