156 



BIOLOGY OF DEATH 



is to these last dots that attention should be particularly 

 directed. It will be noted that the dotted line connecting 

 the last dots of each of the 5 polygons in general rises 

 as we pass from the left-hand side of the diagram to the 

 right-hand side. In the case of offspring dying under 20, 

 24 per cent, of their fathers died at ages over 80. About 



105 



PERSONS 

 DILD 

 60-t 



30 



20 



10 



40 



10 



v 



- 4O 60 8O - 4O 6O 80 - 40 6O 8O - 4O 6O 80 - 4O 6O 8O 

 40 6O 6O + 40 60 6O + 4O 6O 60 ' + 4O 6O 80 + 40 60 8O + 



FIG. 42. Influence of father's age at death upon longevity of offspring. First dot in 

 each diagram shows the percentage having fathers who died at 40; second dot the percent- 

 age having fathers who died from 40-60 ; third dot the percentage having fathers who died 

 from 60-80; fourth dot the percentage having fathers who died 80+ (After Bell). 



21 per cent, of the fathers of offspring dying between 20 

 and 40 lived to be 80 years or over. For the next longer- 

 lived group of offspring, dying between 40 and 60, the 

 percentage of fathers living to 80 or over rose to 27 per 

 cent. In the next higher group, the percentage is nearly 

 38, and finally the extremely long-lived group of offspring, 

 the. 185 persons who died at ages of 80 and over, had 46 

 per cent, or nearly one-half of their fathers living to the 

 same great age. In other words, we see in general that 

 the longer-lived a group of offspring is, on the average, 

 the longer-lived are their fathers, on the average; or, 

 put in another way, the higher the percentage of very 



