a note which is peculiar to times of distress, and followed it thus until finally it disappeared in a hedge. The rapidly uttered note and the excitement of the birds caused some commotion, and the male from an adjoining territory approached the scene. Now one would have expected that the presence of this bird, and possibly its aid in driving away a common enemy, would have been welcomed; one would have thought that all else would have been subservient to the common danger, and that so real a menace to the offspring would have evoked an impulse in the parent powerful enough to dominate the situation and subordinate all the activities of the bird to the attainment of its end. But what happened? Three times during this incident, the male, whose young were in danger, abandoned the pursuit of the Weasel and pursued the intruder. It was not merely that he objected to the presence of this neighbouring male in a passive way, nor even that he had a momentary skirmish with it, but that he determinedly drove the intruder beyond the boundary and only then returned to harass the Weasel.
Thus it seems clear that the proximate end to which the fighting is directed is not necessarily the defeat of the intruder, but its removal from a certain position. And inasmuch as this result will be obtained whether the retreat is brought about by fear of an opponent or by physical exhaustion, it is manifest that too much significance need not be attached to the amount of
