THE INHERITANCE OF FAMILY TRAITS 147 



Table X 



DISTRIBUTION OF DEATHS FROM CANCER IN AGE GROUPS 



At death period 40-49 50-59 60-69 70-80 



Per cent of all deaths 



from cancer 17.1 24.4 25.8 17.1 



Proportion of cancer 



deaths to all deaths 



at that age period 8.3 11.2 10.1 7.0 



like typhoid fever, still not all who are non-resistant will 

 die from cancer because some will not become inoculated. 

 The answer to the question of the ''heredity of cancer" 

 is not to be sought in mass statistics — ^in the correlation of 



Dt6 



KU^ 



^iG. 122. — Pedigree of cancer. In the first generation cancer is admitted. 

 In the second it is not known to have occurred, but the father died at 71 of a 

 somewhat mysterious disease. In the third generation were two cases of 

 cancer (one "bone cancer")* The fourth generation contains persons who 

 are still young. 



deaths from cancer between parents and children, but only 

 by a careful analysis and comparison of individual families. 

 One then sees in many families no deaths from cancer 

 among 10 to 20 persons dying at cancer age, while in other 

 famihes there will be 2 or 3 or even 4 deaths from cancer 

 among those dying at the cancer age (Fig. 122). Thus in 

 a pedigree that lies before me, half of those who have died 



