A. O. POWYS 
275 
popular method of estimating the births per 1000 of the total population) has been 
to show the proportion of legitimate births per 1000 married women under 
45 years of age. But it is evident from Table XXVII. that this method is liable 
to yield misleading comparisons, for the kinetic fertility is dependent not only 
upon the age of the woman but also upon the age at marriage. This objection of 
course also applies even when the more accurate measure of determining the 
movements in the birthrate is adopted, viz. when the rate is determined not in 
one group under age 45, but in quinquennial groups within that group. In New 
South Wales there has been a decline in each quinquennial group except at age 
under 20 since 1881, as will be seen from the following statement* : 
Ages of Wives 
1871 Birthrate 
per cent. 
1881 Birthrate 
per cent. 
1891 Birthrate 
per cent. 
1901 Birthrate 
per cent. 
15 — 19 year.s 
50-10 
51-60 
47-91 
56-28 
20-2^ „ 
44-15 
45-79 
41-63 
39-70 
25—29 „ 
40-75 
40-52 
35-37 
29-87 
30—34 „ 
33-67 
33-86 
29-23 
22-68 
35—39 „ 
27-04 
27-36 
23-63 
17-25 
40-u 
13-41 
12-89 
11-84 
8-81 
The decline since 1881 is a large one and although there has been an un- 
doubted rise in the age at marriage since that period, the decline cannot all be 
attributed to that rise — though probably much is so due. Prior to 1897 the ages 
at marriages were not tabulated— even if they had been it would not have helped 
us much since the marriages to which the births in 1871 and 1881 were due were 
for the most part contracted in Great Britain — the great majority of the adult 
population then being of British birth. But as has been said the decline is not 
wholly due to the advance in the age at marriage — it is chiefly due I think to the 
Law of Regression so ably formulated and demonstrated by Mr Francis Galton in 
" Natural Inheritance." Whilst the systems of free and assisted immigration were 
adopted in New South Wales the immigrants were of special physique and chiefly 
drawn from the two most fertile classes of the British community, viz. the agri- 
cultural and artisan. Medical examination was necessary before departure from 
Great Britain and thus a differentiated community was obtained. This immigra- 
tion ceased about 1885, and this was followed by tlie smaller decline in 1891 and 
the larger in 1901 — the standard of the fertility of the offspring of the immigrants 
regressing towards that of the population from which they originally sprang. 
What difference there will be in the average issue of women of past generations 
and the ultimate families of the present generation — the age at marriage being 
the same — it is of course impossible to say, but I think a very close estimate may 
be made. Take for instance age at marriage under 20. We see from Table XVII. 
the average family of women of past generations marrying at this age was 8-06. 
This is for women whose husbands may have predeceased them before the end of 
* Vide Report of Decline in the Birth-rate Commission, p. 7. 
35—2 
