PHYSICAL CHARACTERS IX MAN 143 



there are facts which bear such an interpretation, 

 prepotency has not yet received a satisfactory 

 biological explanation, nor is it clear that the bio- 

 logical facts require one. Prepotency is believed to 

 be increased by inbreeding, and differences in vigour 

 or energy are also believed to be involved (Popenoe, 

 1 91 6). Mere dominance does not appear to be 

 sufficient to explain it, and the interactions of factors 

 may be concerned. The term should be used with 

 great care, as no case of individual prepotency has 

 yet been proved. Perhaps the most striking case in 

 man is to be found in the offspring of the Mormon, 

 Brigham Young (see Journal of Heredity, January, 

 1 91 6). In a photograph of some eleven of his 

 daughters by eight different wives each one seems to 

 have been stamped, as it were, with the father's own 

 image, though the resemblance is stronger in some 

 cases than in others, but the characters of the other 

 parent are by no means excluded. The resemblance 

 is particularly striking as regards the strong, firm 

 mouth, the ears, and the nose. But all the daughters 

 are said, by one who knew the family, to be also 

 musical, amiable, adaptable, genuine, sincere, w^arm- 

 hearted, generous, attractive, magnetic and S3'm- 

 pathetic, and temperamental yet reasonable. More- 

 over, all were good mimics and excellent cooks and 

 housewives, having also their father's voice and 

 temperament . This remarkable catalogue of qualities 

 is very well substantiated by an accompanying 

 photograph, which shows a group of motherl}-, kind- 

 hearted women with remarkable similarit}' of features, 

 although the mother's influence is also clear in the 

 differences which appear between half-sisters. This 

 resemblance is perpetuated in the grandchildren, 

 especially the girls, and may be partly attributable 



to assort ative matmg. 



Another question of heredity which I have not 



