A. O. POWYS 
265 
New South Wales for the two years 1901 and 1902, whilst that relating to married 
women living with their husbands at the time of the census of 1901 will be found 
in Part " Conj ugal Condition and Families " of the Census returns. The former 
tables show for married women dying in those years the age at marriage (in 
quinquennial groups), the duration of marriage in single years, and total offspring. 
Limiting the information to the reproductive period, the statistics are shown 
in Table XXI. 
The correlation and regression straight lines were determined for each of these 
series with the results set forth in Tables XXII. and XXIII. 
TABLE XXII. 
General Results. 
Age at Marriage 
Mean Duration 
of Life after 
Marriage (within 
Keproductive 
Period) 
Mean 
Size of 
Family 
Standard Deviation 
Correlation. 
Duration of Life 
after Marriage 
and Size of 
Family 
Eegression 
Duration of 
Life after 
Marriage 
Size 
of 
Family 
Under 20 
20 and under 25 
25 „ 30 
30 „ 35 
16-7648 years 
12-6961 „ 
9-3217 „ 
6-8762 „ 
4-9155 
3-8670 
2-8398 
2-0000 
7-9165 years 
7-2585 „ 
5-7459 „ 
4-1622 „ 
2-0168 
1-8226 
1-4459 
1 -0963 
-97328+ -00133 
•96554+ -00143 
-94568 ± -00362 
-65700+ -03812 
-24796 
•24245 
-23797 
•17304 
TABLE XXin. 
Regression Formnlce. 
A' = Duration of Life after Marriage (within Reproductive Period). y = Number of Offspring. 
Age at Marriage, Under 20 years, _?/ = -7585 + -24796.c 
„ „ 20 and under 25 years, _y = -7888 + -24245.j; 
25 „ 30 „ ?/ = -6215 + -23797.?: 
„ „ 30 „ 35 „ ?/ = -8101+-17304.r 
N^ote: — Origin at marriage and unit of .};=1 year. 
The statistics and regression straight lines will be found plotted on Figs. 11, 
12, 18 and 14; the average number of offspring for each year of life after marriage 
is shown by small circles, and that for quinquennial periods by triangles. It 
is seen that in each series although the statistics are somewhat irregular they are 
well represented by the straigiit lines, and thus it would appear that the initial 
fertility incidental to the age at marriage is preservefl almost unchanged through- 
out the reproductive period. It must be clearly understood that the foregoing 
are the results of women dying who had been married and whose husbands may 
or may not have survived them. Although it is seen that the initial fertility 
is preserved throughout the whole of the reproductive period, yet the age at 
marriage is the determinant of that fertility. Up to age 30 there would seem 
to be but little difference in this initial fertility, although it is slightly less at 
Biometrika iv 34 
