HEREUITARY SYNDACTYLISM AND 

 POLYDACTYLISM. 



By J. S. MANSON, M.D. 



In the study of luuuan genetics digital abnormalities present special 

 features as compared with other hereditary abnormalities. As a rule the 

 condition of digital abnormality is so self-evident that it catinot be mis- 

 taken even by an unobservant mind for anything else. Again, affected 

 persons are somewhat proud of this condition, or at least make no 

 attempt at its concealment, so that when it appears in a family the 

 members are usually well informed as to their affected and unaffected 

 relatives even for one or more generations back. This is a great advan- 

 tage to the investigator in human heredity because he has to rely so 

 much on personal statements and memories regarding the condition of 

 distant and dead relatives. Thus, personal statements regarding the 

 presence or absence of digital abnormality have a greater degree of 

 accuracy than similar statements regarding other human hereditary 

 abnormalities such as those of the eye, skin, etc., which require special 

 skill for their diagnosis from acquired conditions. 



The family described in this article originated from one William 

 Joseph who was born and lived at Aberystwith in Wales about the 

 beginning of the 19th century. This man was affected with webbing of 

 the 3rd and 4th fingers on the hands, and had 6 toes on each foot. 



In the accompanying pedigi-ee 64 descendants are shown of whom 

 27 are affected, 33 unaffected, and 4 doubtful. 



The chief branches of the family live in Warrington, Widnes and 

 Salford, and all those alive in these places with the exception of 3 have 

 been seen and examined by the WTiter, and two photographs of the 

 remaining 39 have been seen, leaving the condition of 37 to be ba.sed 

 on the statements of the writer's informants who are themselves 

 members of the 3rd generation. 



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