PHYSICAL CHARACTERS IX jVIAN 89 



" an inhibitory influence checks their development 

 at a stage a few days later than that which checks 

 the formation of the ossification centres and produces 

 brach3^dactyly." Hence both are conditions of 

 arrested development in different degree. 



The original member of this " straight-fingered " 

 famil}^ Wilham B., migrated from Scotland to 

 Virginia in 1700. He married, and from him are 

 descended seven generations, most of whom still live 

 in the same region of Virginia. A member of the 

 fifth generation has communicated with a Scottish 

 relative w^ho shows the trait. The inheritance is that 

 of a Mendelian dominant, the family including 452 

 individuals in eight generations. Of the 150 children 

 of an affected parent in twent3'-eight completed 

 families, seventy-eight of them, or 52 per cent., 

 carried the trait. There is considerable variation in 

 the expression of the character, and the trait ma}' be 

 transmitted in extreme form b}' a parent who appears 

 to be but slightly affected. In one case a woman who 

 was doubtfull}' abnormal, but transmitted the trait, 

 was shown by radiogram to have the condition only 

 on the little finger of one hand. 



Another family with the same peculiarity of fingers, 

 which cannot be flexed properly, is described by 

 Duncan (191 7). It is perhaps related to Cushing's 

 family, since its ancestors are said also to have come 

 from Scotland. The second joints of the fingers, 

 and frequently also of the toes, are perfectly inflexible. 

 The character is a Mendelian dominant and is traced 

 through four generations, the original affected parent 

 (male) being apparently heterozygous. 



Another pedigree of a short-fingered family is given 

 by Mohr and Wriedt (191 9), who review the literature 

 of brachydact3dy. The case they describe, with 

 numerous photographs and radiographs, is of a 

 Norwegian family, some of whose members migrated 



