s; they actually behave as if they were continuously
attentive, looking forward beyond the immediately present experience in
preparation for what is to come. They apparently watch, wait, search,
are on the alert. They also behave exactly as if they appreciated a
difference between relative success and failure, trying again when a
certain perceptible result is not attained and varying their procedure
in so far as it has been unsuccessful. All these characters are found in
the first nest-building of birds as well as in the second; they are
found also in courses of conduct which occur only once in the lifetime
of the animal." Both these writers would, I imagine, contend that, even
when a female is absent, the idea of the female, as the end in view
throughout, is present; and they would argue that the fact of her
absence during the fighting in no way disposes of the belief that she is
the condition under which the pugnacious instinct of the male is
rendered susceptible to stimulation. What reason is there to think that
this interpretation is applicable to the case under consideration? When
a female is present, we observe that the males are pugnacious, and, when
she is absent, that they still continue to be hostile--that is to say,
they behave _as if_ she were present. Now, as far as I can ascertain,
the "_as if_" is the only ground there is for supposing that the female
is represented in imaginal form--there is no evidence of the fact, if
fact it be. On the contrary, the behaviour of the male affords some
fairly conclusive evidence that no such image is the primary factor in
exciting the instinctive reaction. For if it be the actual presence of
the female, or, in the absence of such, a mental image, that renders the
pugnacious nature of the male responsive; provided the usual stimulus
were present, the instinct ought surely to respond, not only under one
particular circumstance, but under all circumstances. Yet, as we shall
presently see, a male is by no means consistently intolerant of other
males. It may be sociable at one moment or pugnacious at another, but
the pugnacity is always peculiar to a certain occasion--the occupation
of a territory. What shall we say then--that a mental image is a
situational item only when the territory is occupied? It may be so; it
may be that the fact of occupation gives rise to the mental image which,
in its turn, renders the fighting instinct explosive, which again
renders the possession of