deduced therefrom a "law of battle," which, he believed, bore
a direct relation to the possession of a female. And it must be admitted
that he had excellent ground for his conclusion in the fact not only
that the conflicts occur mainly during the pairing season, but that
the female is often a spectator and seems even to pair with the victor.
I accepted it, therefore, as the most reasonable interpretation of the
facts. But, as time passed by, incidents of a conflicting character led
me to think that after all there might be another solution of the
problem. And when it was no longer possible to doubt that there was a
widespread tendency to establish territories, it at once became manifest
that the battles might have an important part to play in the whole
scheme. But how was this to be proved? What sort of evidence could show
whether the proximate end for which the males were fighting had
reference to the female or to the territory? Clearly nothing but a
complete record of the whole series of events leading up to reproduction
could supply the necessary data upon which a decision might rest. In the
present chapter I shall give, in the first place, the reasons which lead
me to think that the origin of the fighting cannot be traced to the
female; afterwards, the evidence which seems to show that it must be
sought in the territory; and finally, I shall make a suggestion as to
the part the female may play in the whole scheme.

[Illustration: Male Blackbirds fighting for the possession of territory.
The bare skin on the crown of the defeated bird shows the nature of the
injuries from which it succumbed.

Emery Walker ph.sc.]

The facts upon which the "law of battle" was founded were ample to
establish the truth of its main doctrine. But the evidence upon which
the interpretation of the battles was based was somewhat superficial. It
was based mainly upon the general observation that one or more females
could frequently be observed to accompany the combatants; and if this
were the sole condition under which the fighting occurred, one must
admit that this view would have much to recommend it. But it is not
merely a question of males disputing in the presence of a female; for
males fight when no female is present, pair attacks pair, or a male may
even attack a female--in fact there is a complexity of strife which is
bewildering.

In attributing the rivalry to the presence of the female, it is assumed
that males are in a preponde