THE INHERITANCE OF DURATION 



165 



Prom the first line of this table it is perceived that 

 the total increase in expectation of life which would 

 result if Fisher's ratios of preventability were fully 

 realized is just under 13 years! How unfavorably this 

 contrasts with the 20 years increase shown by the two 



TABLE 16 b Continued 



corner diagonal cells of Table 16! No more striking 

 demonstration could be found of the overwhelming im- 

 portance of heredity in determining duration of life. For 

 if all the deaths which reason will justify one in suppos- 

 ing preventable on the basis of what is now known, were 

 prevented in fact the resulting increase in expectation 

 of life falls seven years short of what might reasonably 

 be expected to follow the selection of only one generation 

 of ancestry (the parental) for longevity. 



So much for Bell's analysis of longevity in the Hyde 



