any insects are
exquisitely adapted for sucking the nectar of flowers; many others would
wish to do the same, but their want of adaptation baffles them.

It is plain that an instinct, or any other form of disharmony, leading
to destruction, cannot increase or even endure very long. The perversion
of the maternal instinct, tending to abandonment of the young, is
destructive to the stock. In consequence, individuals affected by it do
not have the opportunity of transmitting the perversion. If all rabbits,
or a majority of them, left their young to die through neglect, it is
evident that the species would soon die out. On the contrary, mothers
guided by their instinct to nourish and foster their offspring will
produce a vigorous generation capable of transmitting the healthy
maternal instinct so essential for the preservation of the species. For
such a reason harmonious characters are more abundant in nature than
injurious peculiarities. The latter, because they are injurious to the
individual and to the species, cannot perpetuate themselves
indefinitely.

In this way there comes about a constant selection of characters. The
useful qualities are handed down and preserved, while noxious characters
perish and so disappear. Although disharmonies tend to the destruction
of a species, they may themselves disappear without having destroyed the
race in which they occur.

This continuous process of natural selection, which offers so good an
explanation of the transmutation and origin of species by means of
preservation of useful and destruction of harmful characters, was
discovered by Darwin and Wallace, and was established by the splendid
researches of the former of these.

Long before the appearance of man on the face of the earth, there were
some happy beings well adapted to their environment, and some unhappy
creatures that followed disharmonious instincts so as to imperil or to
destroy their lives. Were such creatures capable of reflection and
communication, plainly the fortunate among them, such as orchids and
certain wasps, would be on the side of the optimists; they would declare
this the best of all possible worlds, and insist that to secure
happiness it is necessary only to follow natural instincts. On the other
hand, the disharmonious creatures, those ill adapted to the conditions
of life, would be pessimistic philosophers. Consider the case of the
ladybird, driven by hunger and with a preference for honey, which
s