458 THE POPULAR SCIENCE MONTHLY. 



development has ceased. If mental growth be unduly forced before 

 structural completion, structural and sexual genesis are retarded or 

 impaired. Professional training in women must, therefore, fall within 

 the child-bearing period. In the case of men of great mental activity 

 there is marked impairment of fertility. 1 The cost of reproduction to 

 males is greatly less than to females, and it therefore follows clearly 

 that the prolonged and intensified mental growth, the result of profes- 

 sional training, is to be deducted in full from the sum of the forces 

 necessary to reproduction. M. Quetelet cannot doubt the influence of 

 professional life upon fertility. 2 Mr. Herbert Spencer says, " that abso- 

 lute or relative infertility is generally produced in women by mental 

 labor carried to excess, is more clearly shown. . . . This diminution 

 of reproductive power is not shown only by the greater frequency of 

 absolute sterility, nor is it shown only in the earlier cessation of child- 

 bearing, but it is also shown in the very frequent inability of such 

 women to suckle their infants. In its full sense, the reproductive 

 power means the power to bear a well-developed infant, and to supply 

 that infant with the natural food for the natural period." 3 



Even were it not that absolute and relative infertility are against 

 the woman undergoing severe mental discipline having children to 

 inherit her improved cerebral evolution, and in favor of the average or 

 inferior woman, still the very condition of this mental discipline, if 

 the woman is preparing for the professions or skilled labor, involves a 

 postponement of marriage to a period when, in the mass of wives, 

 fecundity has received a permanent check. The average individual 

 wife shows a degree of fecundity which, at the age of twenty-five, di- 

 minishes, 4 and this is the period at which the professional woman is 

 prepared to enter upon her business career. The opinion of Mr. Sad- 

 ler, that delayed marriages developed a degree of fertility in women 

 which compensated for the loss of fecundity consequent upon the delay, 

 is completely overthrown by the tables of Dr. Duncan. 5 If women are 

 to enter the learned professions and skilled labors, they must be devot- 

 ing themselves to training at a period of their lives when the mass of 

 women are wives mothers. I think that it must be conceded as a 

 fact that, to contract matrimony during this period of mental and 

 bodily training, would totally defeat the selected life-work of the 

 woman. The desire to become the co-worker with man upon the high- 

 est level of man's work belongs only to superior women ; if, in addition 

 to this innate superiority, we add that acquired from increased cere- 

 bral development, the law of heredity would tend to continually en- 



1 " Principles of Biology," ii., p. 487. 



2 A Treatise on "Man and the Development of his Faculties." Translation. Edin- 

 burgh, 1842, p. 21. 



3 Loc. cit, p. 486. 



4 Dr. Matthews Duncan, "Fecundity, Fertility, Sterility, and Allied Topics," Edin- 

 burgh, p. 43. 6 Sadler, " The Law of Population," ii., p. 279. 



