st kind of
ideals of sexual selection, and find themselves quite unable to act on
them. The college woman may have a definite idea of the kind of husband
she wants; but if he never seeks her, she often dies celibate. The young
man of science may have an ideal bride in his mind, but if he never
finds her, he may finally marry his landlady's daughter. Opportunity for
sexual selection must be given, as well as suitable standards; and while
education is perhaps improving the standards each year, it is to be
feared that modern social conditions, especially in the large cities,
tend steadily to decrease the opportunity.

Statistical evidence, as well as common observation, indicates that the
upper classes have a much wider range of choice in marriage than the
lower classes. The figures given by Karl Pearson for the degree of
resemblance between husband and wife with regard to phthisis are so
remarkable as to be worth quoting in this connection:

All poor +.01
Prosperous poor +.16
Middle classes +.24
Professional classes +.28

It can hardly be argued that infection between husband and wife would
vary like this, even if infection, in general, could be proved.
Moreover, the least resemblance is among the poor, where infection
should be greatest. Professor Pearson thinks, as seems reasonable, that
this series of figures indicates principally assortative mating, and
shows that among the poor there is less choice, the selection of a
husband or wife being more largely due to propinquity or some other more
or less random factor. With a rise in the social scale, opportunity for
choice of one from a number of possible mates becomes greater and
greater; the tendency for an unconscious selection of likeness then has
a chance to appear, as the coefficients graphically show.

If such a class as the peerage of Great Britain be considered, it is
evident that the range of choice in marriage is almost unlimited. There
are few girls who can resist the glamor of a title. The hereditary peer
can therefore marry almost anyone he likes and if he does not marry one
of his own class he can select and (until recently) usually has selected
the daughter of some man who by distinguished ability has risen from a
lower social or financial position. Thus the hereditary nobilities of
Europe have been able to maintain themselves; and a similar process is
undoubtedly taking place among the idle rich who o