220 MARRIAGE AND HEREDITY 



may be solved in the future relations of the sexes 

 we can only surmise. As civiKsation tends to foster 

 in us a faculty of self-regulation, — the subordination 

 of private to public interests, — it may become 

 obligatory upon families or communities to keep 

 exact genealogical records, showing the moral pedi- 

 gree of every one of their members. Under this 

 system, when a marriage was proposed the moral 

 pedigrees of the parties would be consulted, and 

 their fitness or unfitness for each other ascertained. 

 Supposing both to have a particular form of con- 

 genital weakness likely to be fostered in their off- 

 spring, the marriage would be pronounced inex- 

 pedient, and public opinion would uphold the ruling. 

 And while unions likely to breed mental or physical 

 disease would be rendered difficult, if not impossible, 

 by the force of public sentiment, those favourable to 

 the species would be encouraged. It would not 

 follow that any great number of people would be 

 disqualified for marriage altogether, although no 

 doubt this would happen in certain cases. They 

 would be compelled to choose their partners upon 

 rational principles, every tendency to degeneration 

 being as far as possible counteracted. 



The known dangers of consanguinity have already 



