and
reproduction is secured.

[Illustration: A battle between two pairs of Jays

Emery Walker ph.sc.]

How then does the whole matter stand? If it were males only that engaged
in serious conflict, and if they fought only in the presence of a
female, the problem would resolve itself into one simply of obtaining
mates. But the warfare extends in a variety of directions, it is not
confined to one sex, nor to unpaired individuals, nor need the opponents
necessarily be of the same sex; it involves both sexes alike singly or
combined. Now the view that the biological end of battle is, in its
primary aspect, related to the female, cannot, as we have seen, apply to
the conflicts between different pairs, and only by much stretching of
the imagination can it be held responsible for the hostility that males
frequently display towards females or _vice versa_. It is valid only for
a certain form of warfare. But that form represents, you will say, a
large proportion of the whole, which is true; and so long as we ignore
the remainder, we might rest content in the belief that we had solved
the major part of the problem. But can we ignore the remainder? Can we
say that the conflicts between paired males, for example, are simply
offshoots of the pugnacious disposition, and have no part to play in the
process of reproduction? They recur with marked persistency season after
season and generation after generation; they are to be found in species
widely remote; they are frequent in occurrence; and no one who had
observed them and noted the vigour with which they are conducted, could,
I think, conclude that they were meaningless--and be satisfied. They
must somehow be explained. So that if anyone thinks fit to maintain that
possession of a mate is an adequate explanation of part of the
hostilities, it is clearly impossible to regard all the fighting as a
manifestation of one principle directed towards a common biological end.

But wherever we extend our researches, we find that the facts give
precision to the view that the occupation of a territory is the
condition under which the pugnacious instinct is rendered susceptible to
stimulation. The Lapwing, when in its territory, displays hostility
towards other males of its own species, but when upon neutral ground,
treats them with indifference; the Chiffchaff pursues its rival up to
the boundary and is then apparently satisfied that its object has been
achieved; the cock Chaffinch in March