March 1, 1918] 



SCIENCE 



205 



riage or to other causes diminishing the 

 proportion of married women of fertile age 

 in the population. The decline has been 

 due rather to a conscious limitation of fer- 

 tility in the large mass of the population. 



The decline in the birth rate, although 

 general, has not been uniformly distributed 

 over all sections of the eommunitj-. It has 

 alfected primarily those economic and so- 

 cial groups which, as we have shown for 

 France, are best able to bear and maintain 

 a good-sized family. Thus, we find that 

 the number of legitimate births per 1,000 

 married males under 55 years in England 

 and Wales was 119 for the upper and mid- 

 dle classes and 213 for the unskilled work- 

 fnen, with a maximum of 230 among the 

 miners.*** The birth rate is greater as the 

 economic and social status is lower. 



Internal changes of popidation are ta- 

 king place in England very similar to 

 those observed in France. Under the in- 

 fluence of the decreasing birth rate the aver- 

 age age of the population of England and 

 Wales is rising and the proportion of old 

 persons is, of course, correspondinglj- in- 

 creasing. If we keep in mind also that 

 the mortality rates of females at the adult 

 ages are progressively lower than those for 

 jnales we are not surprised to find that the 

 increasing proportion of old people is 

 greater among females than among males. 

 While there were, for example, 119 females 

 per 100 males in 1871 at the ages sixty-five 

 and over, the number in 1911 had become 

 132. The disturbing element in this pic- 

 ture is that the population is growing older 

 not only through the increased longevitj* 

 of its constituents but more especially 

 through the decreasing reenforcement 

 from its youth and, due to the operation of 

 mortality, that there is a progressive ex- 



10 Annual Report of the Registrar-General of 

 Births, Deaths and Marriages in England and 

 Wales, 1912, p. xxiii. 



cess of females over males at the older ages. 

 The situation in England may be summed 

 up in the words of her leading demog- 

 rapher, Sir J. Athelstane Baines, as fol- 

 lows : 



In the last forty years, the proportion of people 

 of an age to marry has materially increased, but 

 they marry less and later in life, and thus, to some 

 extent, cause a reduction in the number of births. 

 The main cause of the falling birth rate, however, 

 is the deoliae in the fertility of the married, due to 

 the voluntary restriction of childbearing, a de- 

 cline which has been especially rapid since the 

 beginning of the century. The effects of the fall 

 in the birth rate have been neutralized, until within 

 the last few years, by a still greater fall in the 

 death rate. The improvement has not been so 

 marked among the very young and the old as at 

 adolescence and in the prime of life. While, there- 

 fore, the rate of natural increase has diminished 

 less than the fall in the birth rate would indicate, 

 it has been maintained at the expense of the young. 



As the proportion of infants with a high mortality 

 decreased that of the ages of low mortality in- 

 creased. The death rate went down, and the bal- 

 ance of population became economically favorable. 

 But as the supply of infants diminishes relatively to 

 the rest of the community, and their elders pass 

 from their prime into the time of life when mortal- 

 ity is heavy, the proportionate supply of potential 

 parents of the most ])rolific ages tends to decrease, 

 the birth rate falls more rapidly, and the death rate 

 begins to rise, leaving the margin of natural in- 

 crease alarmingly narrow. The result is an older 

 and less vigorous people; and as the vitality of 

 women is greater than that of men, more of th'e 

 former sex reach maturity, and they last longer, 

 so that a relatively small and probably wholesome 

 numerical superiority at the working ages is con- 

 verted into a growing preponderance of old women 

 in the vale of life." 



I shall now present the situation for the 

 United States. Superficially, the facts of 

 American population growth present a 

 verj' favorable picture. Each successive 

 census has shown a marked increase in our 

 total population over the preceding one; 

 that for 1910 showed an increase of nearly 

 16 million lives over 1900, or 21 per cent. 



II Baines, Sir J. Athelstane, op. cit., p. 413. 



