428 Life and Immortality. 
life, or we fail to remember how largely these songsters, or 
their eggs, or their nestlings, are destroyed by birds and 
beasts of prey. Yes, we do not always bear in mind that, 
though food may now be superabundant, it is not so at all 
seasons of each recurring year. The term, Struggle for 
Existence, must be used in a large and metaphorical sense. 
It must be construed to include the dependence of one being 
on another, and also not only the life of the individual but 
also its success in leaving offspring. Two carnivores, in a 
time of scarcity of food, may be truly said to struggle with 
each other for maintenance of life. Buta plant on the edge 
of a desert is said to struggle for life against the drought, 
though, properly speaking, it is dependent for its existence 
upon the moisture. A plant, however, that annually produces 
many thousand seeds of which on an average only one comes 
to maturity, may in a much truer sense be said to struggle 
with the plants of the same and other kinds which already 
invest the ground. While the mistletoe is dependent on the 
apple and some other trees, yet it cannot be said, unless in a 
far-fetched sense, to struggle with these trees, for, if too 
many of these parasites are found upon the same tree, it will 
certainly languish and die. Several seedling mistletoes, how- 
ever, growing close together upon the same branch, may 
more truly be said to struggle with each other. 
From the high rate at which all organic beings tend to 
increase, there must inevitably follow a Struggle for Existence. 
Every being which, during its natural lifetime, produces 
several eggs or seeds, must necessarily suffer destruction 
during some part of that period, and during some season or 
occasional year, otherwise, on the principle of Geometrical 
Increase, its numbers would become so inordinately exces- 
sive that no country would be able to support its product. 
Therefore, as more individuals are produced than can pos- 
sibly survive, there must be in every case a Struggle for 
Existence, either one individual struggling with another of 
the same kind, or with individuals of distinct kinds or species, 
