272 Diiratioti of Marriage and Number of Ojfsjjrlng 
births ai'e about 300 per 1000 married women marrying under 25 years. But if 
marriage be delayed beyond that age, not only is the initial fertility reduced, but 
it apparently diminishes with the duration of marriage. As has already been 
shown, it is impossible to obtain from the census returns the results of marriages 
within quinquennial groups of age at marriage, but it can be obtained in decennial 
groupings, though, for reasons previously set forth, not for all such marriages. 
Thus, those women whose ages at the census were between 30 and 35 years, 
and whose duration of marriage was under 5 years, must have been married 
between the ages of 25 and 35, as also those who were aged 35 to 40, and had 
been married 5 to 10 years, and so on. In this way was obtained the information 
relating to women marrying at ages 25 to 35, and also upon the same principle 
that of women marrying at ages 35 to 45. The results are shown in Table XXVI. 
Fig. 16. Women Married under 25. 
9 
8 
7 
I' 6 
3 
2 
1 
0 5 10 15 20 25 
Duration of Marriage [Years). 
Eegression Straight Lines : 
aa' (Census), y = -.3450 + -30286*; ) Origin at Marriage. 
hb' (Deaths), ;/ = -7360 + ■24840.r ) Unit of .r = l year. 
It would now be well to show side by side the average families and proportion 
of wives without issue for each age at marriage and each duration of marriage. 
This is done in Table XXVII. The second column in that table shows tlie mean 
age at marriage of those marrying within the groups shown in the first column 
according to the experience of the years 1897 to 1902, when the ages were shown 
in single years. 
These results are shown graphically in Figure 17 — except for marriages under 
20. The table shows in a striking manner the effects of delayed marriage and how 
the generative organs in females tend to become atrophied through non-use. For 
marriages contracted under age 25 we see that only 2^ per cent, are sterile at the 
end of the reproductive period, whilst for marriages contracted between 25 and 35 
or at a mean age of 28-4 years the percentage is nearly 12, and for ages 35 to 45 
.a 
a 
