282 
Reproductive Selection 
class, and fortunately I have been able to obtain these with a great degree of 
accuracy. The total number of males over 20 years of age in each class was 
obtained at the census of 1901, and the occupations of the bridegrooms have also 
been obtained for the year8 1901 and 1902, and which are publislied in the "Vital 
Statistics " of New South Wales for those years. Hence the marriage rates 
per 1000 adults of each can readily be ascertained. The statistics and results are 
shown in Table XXIX. 
TABLE XXIX. 
Marriage Rates of Various Classes of Occupations. 
Class of Occupation 
Number of Adults 
(20 upwards) at 
Census 1901 
Number of 
Marriages 
Mean of Years 
1901 and 1902 
Marriase Rate 
per 1000 
Adults 
Index No. 
Mean = 1 
Professional 
23300 
764-5 
32-81 
1-181 
Domestic ... 
17277 
272 
15-72 
-566 
Commercial 
91939 
2759-5 
29-99 
1-079 
Industrial ... 
102071 
4130-5 
40-46 
1-456 
Agricultural, Pastoral, and Mining 
139947 
2545-5 
18-18 
-654 
Indefinite ... 
3575 
39-5 
Total 
378109 
10511-5 
27-79 
By applying the index number shown in the last column to the net fertility 
shown in Table XXVIII. we obtain finally as the comparative net fertility : 
1st, Industrial Class 5-502, 
2nd, Professional ^ „ 3-861, 
3rd, Commercial „ 3"784, 
4th, Pastoral, Agricultural, &c. „ 3-142, 
5th, Domestic ,, 1-945. 
Thus although natural selection failed to change the position of the classes in 
the net fertility from those occupied in the gross yet the class marriage rates have 
completel}' done so. The rural class with the highest gross and net fertilities, 
with the least mortality amongst the offspring, and also as we shall presently see 
with the lowest adult mortality, now falls to nearly the lowest position, whilst the 
industrial class with both these mortalities the highest occupies the highest position 
through the frequency of mating in that class. We have seen that the average 
gross fertility of the agricultural and pastoral class is 6'149, and the industrial 5-187 
— merely a difference of one child per father ; but this difference is probably not 
altogether due to a difference in actual fertility but to the heavier adult mortality in 
the latter class and consequently shortened life. This will be seen from the following 
