e in Malthus. Fancy a young man who believes in Malthus! They
seem in no hurry at all to get married. But thirty or forty years ago,
young men used to rush by blind instinct into the toils of
matrimony--because they couldn't help themselves. Such Laodicean
luke-warmness betokens in the class which exhibits it a weakening of
impulse. That weakening of impulse is really the thing we have to
account for.

Young men of a certain type don't marry, because--they are less of young
men than formerly.

Wild animals in confinement seldom propagate their kind. Only a few
caged birds will continue their species. Whatever upsets the balance of
the organism, in an individual or a race tends first of all to affect
the rate of reproduction. Civilise the red man, and he begins to
decrease at once in numbers. Turn the Sandwich Islands into a trading
community, and the native Hawaiian refuses forthwith to give hostages to
fortune. Tahiti is dwindling. From the moment the Tasmanians were taken
to Norfolk Island, not a single Tasmanian baby was born. The Jesuits
made a model community of Paraguay; but they altered the habits of the
Paraguayans so fast that the reverend fathers, who were, of course,
themselves celibates, were compelled to take strenuous and even
grotesque measures to prevent the complete and immediate extinction of
their converts. Other cases in abundance I might quote an I would; but I
limit myself to these. They suffice to exhibit the general principle
involved; any grave upset in the conditions of life affects first and at
once the fertility of a species.

"But colonists often increase with rapidity." Ay, marry, do they, where
the conditions of life are easy. At the present day most colonists go to
fairly civilised regions; they are transported to their new home by
steamboat and railway; they find for the most part more abundant
provender and more wholesome surroundings than in their native country.
There is no real upset. Better food and easier life, as Herbert Spencer
has shown, result (other things equal) in increased fertility. His
chapters on this subject in the "Principles of Biology" should be read
by everybody who pretends to talk on questions of population. But in new
and difficult colonies the increase is slight. Whatever compels greater
wear and tear of the nervous system proves inimical to the reproductive
function. The strain and stress of co-ordination with novel
circumstances and novel relations affect m