PHYSICAL DEGENERACY OR RACE SUICIDE? 513 



1. The decline in the birth rate is not merely the result of an altera- 

 tion in the ages of the population, or in the number or proportion of 

 married women, or in the ages of these. 



It is necessary at the outset to remove one possible explanation. 

 What the Eegistrar-General gives us is the crude birth rate — that is to 

 say, the exact proportion of births during the year to the total popula- 

 tion, whether old or young, married or single. But in comparing these 

 birth rates for different years, we have to remember that important 

 changes may take place, even in a single decade, in (a) the proportion 

 between children and adults; (&) the proportion between married and 

 unmarried; and (c) the proportion between married women of the re- 

 productive age and those above that age. These changes — due, it may 

 be, to emigration or immigration, to economic or social developments, 

 or to mere prolongation of the average life — are sufficient, in them- 

 selves, to produce a rise or a fall in the crude birth rate, without there 

 having been any increase or decrease in human fertility. To give one 

 striking instance, the crude birth rate of Ireland per 100,000 popula- 

 tion fell from 2,384 in 1881, to 2,348 in 1901. But we happen to know 

 that in the course of these twenty years the proportion of married 

 women of reproductive age to the total population so far diminished 

 that the slight fall in the crude birth rate really represented, not a 

 decline, but a positive increase in fertility. If the Ireland of 1901 

 had contained a population made up, by ages, sexes and marital condi- 

 tions, in the same proportion as that of 1881, the recorded births in 

 1901 would have appeared as a birth rate actually higher by 3 per cent, 

 than that of 1881. We have, therefore, first to ask what are the cor- 

 responding figures for England and Wales, eliminating all the elements 

 of variations of age, of postponement of marriage, and of positive re- 

 fusal to marry. 3 



Now, it so happens that this problem has lately been worked out by 

 the statisticians in a way to remove all uncertainty. Dr. Arthur News- 

 holme and Dr. T. H. C. Stevenson on the one hand, and Mr. G. Udny 

 Yule on the other, have performed the laborious task of ' correcting ' 

 the crude birth rates for differences of age, sex and marital conditions, 

 as regards the census years from 1861 to 1901. 4 The results show a 



3 1 have restricted myself throughout to legitimate births. The number of 

 illegitimate births in England and Wales is now only 112 per 10,000 of the popu- 

 lation, and their omission does not affect the result. Their inclusion would 

 merely have intensified the force of the argument at all points. The corrected 

 illegitimate birth rate fell between 1861 and 1881 by 21 per cent., and between 

 1881 and 1901 by 41 per cent. — more than twice as fast as the correct legitimate 

 birth rate. 



4 The decline of human fertility in the United Kingdom and other coun- 

 tries as shown by corrected birth rates, by Arthur Newsholme, M.D., medical 

 officer of health, Brighton; and T. H. C. Stevenson, M.D., assistant medical officer 

 to the Education Committee of the London County Council. 



vol. lxviii. — 33. 



