conditions under which animals and plants exist, and have existed
for ages, on this globe. Both animals and plants produce germs, or
young, in excess—usually in vast excess. The world, the earth’s
surface, is practically full, that is to say, fully occupied. Only one pair
of young can grow up to take the place of the pair—male and female
—which have launched a dozen, or it may be as many as a hundred
thousand, young individuals on the world. The property of Variation
ensures that amongst this excess of young there are many
differences. Eventually those survive which are most fitted to the
special conditions under which this particular organism has to live.
The conditions may, and indeed in long lapses of time must, change,
and thus some variation not previously favoured will gain the day
and survive. The ‘struggle for existence’ of Darwin is the struggle
amongst all the superabundant young of a given species, in a given
area, to gain the necessary food, to escape voracious enemies, and
gain protection from excesses of heat, cold, moisture, and dryness.
One pair in the new generation—only one pair—survive for every
parental pair. Animal population does not increase: ‘Increase and
multiply’ has never been said by Nature to her lower creatures.
Locally, and from time to time, owing to exceptional changes, a
species may multiply here and decrease there; but it is important to
realize that the ‘struggle for existence’ in Nature—that is to say,
among the animals and plants of this earth untouched by man—is a
desperate one, however tranquil and peaceful the battlefield may
appear to us. The struggle for existence takes place, not as a clever
French writer
[5]
glibly informs his readers, between different species,
but between individuals of the same species, brothers and sisters
and cousins. The struggle between a beast of prey which seeks to
nourish itself and the buffalo which defends its life with its horns is
not ‘the struggle for existence’ so named by Darwin. Moreover, the
struggle among the members of a species in natural conditions
differs totally from the mere struggle for advancement or wealth
with which uneducated writers so frequently compare it. It differs
essentially in this—that in Nature’s struggle for existence, death,
immediate obliteration, is the fate of the vanquished, whilst the only