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UNIVERSITY OF VIRGINIA. PUBLICATIONS 



While this material does not indicate very definitely the maixaer of the 

 tubercular heredity, i.e., whether it follows Mendelian principles — it clearly 

 reveals, I believe, a definite hereditary aspect of tuberculosis; and that is 

 the all important matter by reason of its eugenic bearing. In the light of 

 pedigree, figure 39, matings where both parents are tubercular would seem 

 to be ill-advised. If the assumptions indicated are correct, then matings 

 between tuberculars and normals would result in normals; but matings 

 between such "normal" offspring would again be in danger of producing a 

 tubercular among every four offspring. The eugenic bearing is obvious; 

 and restrictive measures clearly indicated in the interests of a final control 

 of the "white plague." 





ef.zz. 'f-3'S'.,4.B6: 



ii 



S.J/. s.zo_ 



Fig. 39 Pulmonary Tuberculosis. 



It will suffice to merely state that by hereditary pulmonary tubercu- 

 losis is meant simply the inheritance of a constitutional predisposition or 

 susceptibility or lack of resistance to infection. As to the factors (alle- 

 lomorphs) concerned we can only speculate. Since the pathologic con- 

 dition seems more of the nature of a recessive it is more in accordance with 

 present knowledge to regard the tuberbular diathesis as due to the absence 

 rather than the presence of a factor (determiner). Moreover, the facts of 

 the pedigrees strongly favor such interpretation. Two abnormals here as 

 far as is known had no normal offspring. 



The following two histories of apparently hereditary cancer were secured 

 for me by Mr. Carrington Williams of the University of Virginia. 



