 |
 |
 |
 |
|
 |
 |
Hereditary Genius
xxi
afforded by misery or prudential restraint. Is it true that misery, in any
justifiable sense of that word, provides the only check which acts
automatically, or are other causes in existence, active, though as yet
obscure, that assist in restraining the overgrowth of population? It is certain
that the productiveness of different marriages differs greatly in
consequence of unexplained conditions. The variation in fertility of different
kinds of animals that have been captured when wild and afterwards kept in
menageries is, as Darwin long since pointed out, most notable and
apparently capricious. The majority of those which thrive in confinement,
and apparently enjoy excellent health, are nevertheless absolutely infertile;
others, often of closely allied species, have their productivity increased. One
of the many evidences of bur great ignorance of the laws that govern
fertility, is seen in the behaviour of bees, who have somehow discovered
that by merely modifying the diet and the size of the nursery of any female
grub, they can at will cause it to develop, either into a naturally sterile
worker, or into the potential mother of a huge hive.
Demographers have, undoubtedly, collected and collated a vast amount of
information bearing on the fertility of different nations, but they have mainly
attacked the problem in the gross and not in detail, so that we possess little
more than mean values that are applicable to general populations, and are
very valuable in their way, but we remain ignorant of much else, that a
moderate amount of judiciously directed research might, perhaps, be able to
tell.
As an example of what could be sought with advantage, let us suppose
that we take a number, sufficient for statistical purposes, of persons
occupying different social classes, those who are the least efficient in
physical, intellectual, and moral grounds, forming our lowest class, and
 |
|
 |
|