iS2 Dynamic Evolution 



and living to the age of 55, and so on, then 

 the numbers "60," "65," and "55" were 

 placed in the columns headed "25," "27," 

 and "30," respectively. The average was 

 then found for each column. These averages 

 represented the expectancy of life at the age 

 of twenty-five for brothers and sisters in 

 families of four or more. The total number 

 of individuals was 1105, originally placed in 

 five tables of approximately the same size 

 and afterwards combined into one table. 

 With minor variations, each of the five tables 

 showed the same general result. The full 

 table is as follows: 



Expectancy of Life at Age 25 for 1105 Persons, 



and Relationship of Age of Father at 



Birth of Child. 



Age, of Fathers N jf£Z? ^bJath^ "* 



Under 25 83 62.63 years 



25 to 29 233 65.20 years 



30 to 34 266 65.28 years 



35 to 39 199 65.41 years 



40 to 44 165 68.02 years 



45 to 49 88 66.28 years 



50 and over 71 70.27 years 



1 105 65.89 years 



