LAWS OF THE FERTILITY OF WOMEN. 



303 



"It is thus obvious that marriages formed under the age of 25 are more pro- 

 lific than those formed after that age, and that those formed between 16 and 20 

 years of age are still more so than those at any of the superior ages."* 



As the doctrine generally taught, so far as I know, is exactly the opposite of 

 that here sustained, it is important to establish the latter, if possible, by further 

 proof. At another place I shall show the erroneous interpretation of the data 

 which have been adduced in support of the opposite doctrine— namely, that mar- 

 riages formed late in life are more prolific than those formed earlier. 



The figures now to be adduced not only confirm the doctrine that early mar- 

 riages are more fruitful than late marriages ; they also explain it, showing that 

 the younger married have a longer continuance of fertility than the older married, 

 allowing to both the same duration of marriage, and all within the child-bearing- 

 period of life. So far as the demonstration has hitherto gone, we have shown 

 that the younger are more fertile than the elder ; that, excluding those who have 

 no children, the younger will bear larger families than the older. We have not 

 shown which bear their children most rapidly — that is, which have the greatest 

 intensity of fertility while it lasts — leaving this topic for another chapter. We 

 now proceed to show that, among the fertile, the younger have a longer continu- 

 ance of fertility than the elder. It is this last circumstance which accounts for 

 the greater fertility of the marriages of the younger. The following Table demon- 

 strates this. It needs no explanation. The details are given in the footnote.f 



TABLE IX. — Showing the Amount of Continuance in Fertility of Wives 

 Married at Various Ages (as shown within Twelve Months). 



Age of Mother at Marriage, .... 



15-19 



20-24 



25-29 



30-34 



35-39 



Total. 



The number Child-bearing in the 5th 1 

 year of Married Life is 1 in . . .J 



The number Child-bearing in the 10th "1 

 year of Married Life is 1 in . . .J 



The number Child-bearing in the 15th "1 

 year of Married Life is 1 in . . . / 



The number Child-bearing in the 20th "1 

 year of Married Life is 1 in . . .J 



The number Child-bearing in the 25th "4 

 year of Married Life is 1 in . .J 



26 



2-7 



4-1 



4-9 



10-5 



32 



32 



4-0 



5 9 



8-7 





4 4 



4-6 



6-8 



18-2 



37-4 





80 



8-5 



14-6 



129-8 



... 





163 



680 



480 5 









171-0 



* Journal of the Statistical Society of London, vol. xi. p. 223. 



t The Table IX. may be easily seen to be made up from the following five Tables, X., XL, XII , 

 XIII., Ill V. In these five Tables of the fertility of married life at different epochs, the number of 



VOL. XXIV. PART II. 4 N 



