eks before the real business of reproduction begins. Are we then
justified in regarding them as accidents of the developing situation?
Are we not rather bound to admit that they have some definite biological
end to serve?

[Illustration: Competition for territory is seldom more severe than
amongst cliff-breeding sea birds, and the efforts of individual
Razorbills to secure positions on the crowded ledges lead to desperate
struggles.

Emery Walker ph.sc.]

These examples show that the males of many species reverse their mode of
life at the commencement of the breeding season and proceed to isolate
themselves, each one in a definitely delimited area.

There are three ways in which we may attempt to interpret this
particular mode of male behaviour. We may regard it as an accidental
circumstance, nowise influencing the course of subsequent procedure; or,
appealing to the law of habit formation, we may regard it as an
individual acquirement; or again, we may invest it with a deeper
significance and seek its origin in some specific congenital disposition
determined on purely biological grounds.

Which of these three shall we choose? The first by itself requires but
little consideration; for though it might explain the initial visit, it
cannot account for the persistency with which the plot of ground is
afterwards resorted to. Supposing, however, that we combine the first
and the second; supposing, that is to say, we assume, for the purpose of
argument, that the initial visit is fortuitous, and that constancy is
supplied by habit formation--would that be a satisfactory
interpretation? It is a simple one, inasmuch as it only requires that a
male shall alight by chance in a particular place for a few mornings in
succession in order that the process may be set in motion. Now an
essential condition of habit formation is recurrent repetition; given
this repetition and, it is true, any mode of activity is liable to
become firmly established. But how can we explain the repetition? Even
if we are justified in assuming that the initial visit is purely an
accidental occurrence, we cannot presume too far upon the laws of chance
and assume that the repetition, at first, is also fortuitous.

So that we come back to the congenital basis, the last of our three
propositions. And it will, I think, be admitted that the facts give us
some grounds for believing that the securing of the territory has its
root in the inherited constitution