96 HEREDITY AND SOCIAL FITNESS 



ment of the line, the limitations to selection imposed by the undesira- 

 bility of the unfit as life partners, supplemented by "fear of the 

 blood," have promoted the mating of the same or of different types of 

 unfitness, and have resulted in the persistence and diversification of 

 the original defects. 



Our history furnishes several instances where the undesirableness of 

 the defective as a consort was olTset by the possession of a small patri- 

 mony; but here again the partner selected by designing outside parties 

 was very deficient mentally, or a gross sex-offender. Since it is the 

 policy of some charitable societies to encourage the marriage of sex- 

 offenders, its frightful results, as illustrated in these histories, can not 

 be too sharply stressed. 



Accordingly we may summarize as follows: Marriage selection as 

 determined largely by the innate qualities of the individual has, by 

 the convergence of the innate qualities of the various strains, operated 

 in some lines to dissipate defects and to introduce traits which make for 

 increased social efficiency, and to concentrate defect and degeneracy 

 in other lines. 



