THE CAUSES OF THE DECLINING BIRTH RATE 163 
Mombert from whom the above table is taken states that 
iegitimate fertility in the cities as compared with the land is 
lower, has declined more rapidly and began to decline earlier. In 
the large cities (Grosstddte) the fall in the birth rate has been 
especially rapid. All of the large cities showed a lower corrected 
birth rate in 1901 than the country. The average children per 
1,000 married women (15-45 yrs) in cities of 40,000 in 1901 was 
238 as compared with the rural rate of 337, but this rate was 
higher than that of most of the larger cities of that year (Berlin, 
172, Breslau, 234, Frankfurt, 208, Munich, 225, Dresden, 211, 
Essen, 328, Hamburg, 194, Leipzig, 209). 
Data on urban and rural birth rates are often greatly affected 
by many factors which tend to obscure the influence of cities 
per se. Much depends upon the kind of industry in which the 
city populations are engaged. Manufacturing cities have, as a 
rule, a higher birth rate than cities which are chiefly engaged in 
commerce, or which are mainly residential. Often the racial 
composition of cities differs considerably from that of the sur- 
rounding country, as is very strikingly illustrated in the United 
States. To a less extent this is true in Europe where the percen- 
tage of persons born outside the country is greater in cities, and 
especially in large cities, than in rural districts. Cities tend to be 
centers of racial mixtures, whatever this may imply as regards 
the birth rate and the quality of the offspring of mixed marriages. 
It is probable that the ratio of males to females would be increased 
by this circumstance, but what other biological effects would 
follow is doubtful. Since the inhabitants of cities may differ from 
those of the surrounding country in race, religion, education and 
prosperity, peculiar combinations of circumstances may render 
even the corrected birth rate of cities higher than that of the 
country. There is abundant evidence, however, that the usual 
effect of an urban environment is to check the propagation 
of the race. 
There is little doubt that one factor in the decline of the birth 
rate is the reduction in infant mortality which has accompanied 
the fall of the death rate in recent decades. The correlation 
