mind, that though food may be now superabundant, it is not so at all
seasons of each recurring year.
I should premise that I use the term Struggle for Existence in a large
and metaphorical sense, including dependence of one being on another,
and including (which is more important) not only the life of the
individual, but success in leaving progeny. Two canine animals in a
time of dearth, may be truly said to struggle with each other which
shall get food and live. But a plant on the edge of a desert is said to
struggle for life against the drought, though more properly it should
be said to be dependent on the moisture. A
plant which annually produces a thousand seeds, of which on an average
only one comes to maturity, may be more truly said to struggle with the
plants of the same and other kinds which already clothe the ground. The
missletoe is dependent on the apple and a few other trees, but can only
in a far-fetched sense be said to struggle with these trees, for if too
many of these parasites grow on the same tree, it will languish and
die. But several seedling missletoes, growing close together on the
same branch, may more truly be said to struggle with each other. As the
missletoe is disseminated by birds, its existence depends on birds; and
it may metaphorically be said to struggle with other fruit-bearing
plants, in order to tempt birds to devour and thus disseminate its
seeds rather than those of other plants. In these several senses, which
pass into each other, I use for convenience sake the general term of
struggle for existence.
A struggle for existence inevitably follows from the high rate at which
all organic beings tend to increase. Every being, which during its
natural lifetime produces several eggs or seeds, must suffer
destruction during some period of its life, and during some season or
occasional year, otherwise, on the principle of geometrical increase,
its numbers would quickly become so inordinately great that no country
could support the product. Hence, as more individuals are produced than
can possibly survive, there must in every case be a struggle for
existence, either one individual with another of the same species, or
with the individuals of distinct species, or with the physical
conditions of life. It is the doctrine of Malthus applied with manifold
force to the whole animal and vegetable kingdoms; for in this case
there can be no artificial increase of food, and no prudential
restraint from marriage. Although some species may be
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