308 



DR MATTHEWS DUNCAN ON THE 



as the mass of figures can be relied on, that the fertility of the elder is greater 

 than of the younger, while it lasts ; or, in other words, the fertility of the elder 

 is the more intense. 



TABLE XVI. — Showing the Intensity - of Fertility- in Wives Mothers of 



Different Ages.* 





Mother's Age. 



Duration of Marriage. 





15-19. 



20-24. 



25-29. 



30-34. 



35-39. 



40-44. 



45-49. 



Under 5 years, . 



1-128 



1-519 



1-825 



1-844 



1-827 



1-698 



1-200 



5 years and under 10, 



2-500 



3-190 



3-750 



4048 



4085 



3-792 



4000 



10 years and under 15, 



... 



5333 



5-453 



5-903 



6197 



5964 



6-500 



15 years and under 20, 





... 



6-000' 



7-379 



7-914 



7-993 



8-435 



20 years and under 25, 





... 



... 



7000 



9-396 



9-718 



10-528 



25 years and under 30, 



... 









... 



12-368 



13-600 





... 





... 





... 



... 



13000 



The conclusion here arrived at is founded upon lengths of married life. Were 

 the figures such as to give, instead of lengths of married life, lengths of intervals 

 between the births of first and last children, the results would be still more 

 striking ; for I have already shown that in the case of the elder, fertility is later in 

 beginning to show itself than in the younger. 



If, as I have shown, the younger are more prolific than the elder, and if, as 

 also I have shown, the elder are more intensely fertile, while their fertility lasts, 

 than the younger in the same time ; then, it necessarily follows, as a corollary, 

 that the fertile women married younger have a longer continued fertility than 

 the fertile women married older. In no other way can the younger surpass the 



* The following Tables give all the details and calculations from which Table XVI. is 

 constructed : — 



TABLE XVII.— Or Women under 5 Years Married. 







No. of 

 Mothers. 



No. of 

 Children. 



Average to 

 each Mother. 





7,183 



11,880 



1-654 



Mother's age — 16 to 19 years, . 



20 to 24 „ . 



25 to 29 „ . 



30 to 34 „ 

 ,, 35 to 39 „ 

 „ 40 to 44 „ 



45 to 49 „ 





374 



3,180 



2,460 



833 



277 



53 



5 



422 



4,829 



4,489 



1,536 



506 



90 



6 



1128 

 1-519 

 1-825 

 1-844 

 1-827 

 1-698 

 1200 



