e struggle for existence is again directly competitive. It is
difficult to separate the struggle for food and foothold from the
struggle for mates, and it seems clearest to include here the battles of
the stags and the capercailzies, or the extraordinary lek of the
blackcock, showing off their beauty at sunrise on the hills.

b) _Struggle between foes._--In the locust swarm and in the rats'
combats there is competition between fellows of the same or nearly
related species, but the struggle for existence includes much wider
antipathies. We see it between foes of entirely different nature,
between carnivores and herbivores, between birds of prey and small
mammals. In both these cases there may be a stand-up fight, for instance
between wolf and stag, or between hawk and ermine; but neither the logic
nor the biology of the process is different when all the fight is on one
side. As the lemmings, which have overpopulated the Scandinavian
valleys, go on the march they are followed by birds and beasts of prey,
which thin their ranks. Moreover, the competition between species need
not be direct; it will come to the same result if both types seek after
the same things. The victory will be with the more effective and the
more prolific.

c) _Struggle with fate._--Our sweep widens still further, and we pass
beyond the idea of competition altogether to cases where the struggle
for existence is between the living organism and the inanimate
conditions of its life--for instance, between birds and the winter's
cold, between aquatic animals and changes in the water, between plants
and drought, between plants and frost--in a wide sense, between Life and
Fate.

We cannot here pursue the suggestive idea that, besides struggle between
individuals, there is struggle between groups of individuals--the latter
most noticeably developed in mankind. Similarly, working in the other
direction, there is struggle between parts or tissues in the body,
between cells in the body, between equivalent germ-cells, and, perhaps,
as Weismann pictures, between the various multiplicate items that make
up our inheritance.

2. Competition and Natural Selection[185]

The term "struggle for existence" is used 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 strug