TIUNSACTIOXS OF SECTION F. 



867 



In both tables the percentages run with great regularity, and the results are 

 very similar in the two ; so that, notwithstanding the comparative smallness of the 

 numbers involved, the results appear entitled to great confidence. 



In order to^ solve the second question proposed, and obtain the probability that 

 a marriage which has been childless for several years will subsequently bsconie 

 fruitful, it is necessary to tabulate the marriages according to the year in which 

 the first child was born. This is done in the following table, which relates to the 

 806 marriages of men under thirty. It shows that 292 of these became fruitful in 

 the first year after marriage, 256 in the second, 72 in the third, and so on, until we 

 come to a single marriage which became fruitful in the seventeenth year, after 

 which none became fruitful. Deducting from the total of 806 the 292 marriages 

 which became fruitful in the first year, and the 4 which were dissolved by the 

 death of either husband or wife, we have 510 unfruitful marriages subsisting at 

 the beginning of the second year, of which 386 (or 76 per cent.) subsequently 

 became fruitful. The figures in the last column are obtained by division from 

 those in the two previous ones, and give the probability required, which, we see, 

 steadily diminishes to 20 per cent, at the beginning of the sixth year, 10 per cent, 

 at the beginning of _ the eleventh, and 1 per cent, at the beginning of the seven- 

 teenth, after which it vanishes. 



K 2 



