CULTURE AND BIRTH-RATES 249 



levels, it hardly amounts to a quarter of what 

 Nature intends it to be. This fall is customarily 

 imputed to the deliberate use of preventives 

 against child-bearing, but we must hesitate to 

 conclude that an artificiality which has not in- 

 fluenced the continuity of the race throughout 

 countless centuries should, within a single genera- 

 tion, have become so widely adopted as to dimin- 

 ish the reproductiveness of a whole population 

 by as much as a third. Undoubtedly it has an 

 effect and a great effect in limiting the size 

 of families amongst certain classes of the com- 

 munity. But we must not forget that the falling 

 birth-rate has been accompanied by changes that 

 are of immense importance to reproductiveness 

 a fall in the proportionate number of marriages, 

 and a rise in the age at which marriage is con- 

 tracted. In England, within the last forty years 

 the proportion of marriageable women that are 

 married has fallen from 57 to 46 per cent. It has 

 been shown by elaborate statistical investigations 

 that woman's potential fertility her prospect of 

 bearing children which is at its maximum when 

 she is 18, diminishes exceedingly rapidly as her 

 age advances : indeed at 28 it has probably fallen 

 by almost 40 per cent. Moreover it seems that 

 a woman who is married in youth maintains her 

 potential fertility longer than one who is un- 

 married in fact, that a woman of 28 who was 

 married at 18 has a better chance of bearing off- 

 spring than a bride of 28. In a less degree man's 

 potential fertility also declines as his age advances 

 over 25. Since the English birth-rate first showed 

 signs of declining forty years ago the average 

 age of brides has risen by 2 years, and that of 

 bridegrooms by 3 years, and the proportion of 

 married women who are under 25 has fallen from 

 15 to 10 per cent. The effect of this change in 



