486 LAWS or MULTIPLICATION. 



better than that of girls belonging to the poorer classes, 

 while, in most other respects, their physical treatment is not 

 worse, the deficiency of reproductive power among them 

 may be reasonably attributed to the overtaxing of their 

 brains an overtaxing tvhich produces a serious reaction on 

 the physique. 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 re- 

 productive power means the power to bear a well- developed 

 infant, and to supply that infant with the natural food for 

 the natural period. Most of the flat-chested girls who 

 survive their high-pressure education, are incompetent to 

 do this. Were their fertility measured by the number of 

 children they could rear without artificial aid, they would 

 prove relatively very infertile. 



The cost of reproduction to males being so much less 

 than it is to females, the antagonism between Genesis and 

 Individuation is not often shown in men by suppression of 

 generative power consequent on unusual expenditure in 

 bodily action. Nevertheless, there are indications that this 

 results in extreme cases. We read that the ancient athleta 

 rarely had children ; and among such of their modern repre- 

 sentatives as acrobats, an allied relation of cause and effect 

 is alleged. Indirectly this truth, or rather its converse, 

 appears to have been ascertained by those who train men for 

 feats of strength they find it needful to insist on con- 

 tinence. 



Special proofs that in men, great cerebral expenditure di- 

 minishes or destroys generative power, are difficult to obtain. 

 It is, indeed, asserted that intense application to mathematics, 

 requiring as it does extreme concentration of thought, is apt 

 to have this result ; and it is asserted, too, that this result is 

 produced by the excessive emotional excitement of gambling. 

 Then, again, it is a matter of common remark how frequently 



