WILLOW WABBLER
conflicts vary much in intensity, appearing sometimes to lack determination and to be more in the nature of play, yet from closely studying the conditions under which they occur I believe that, in the majority of instances, they represent a genuine trial of strength, and that the combatants are in earnest. It is necessary to bear in mind the strength and capability of the actors, and to remember that even the most deadly of contests must always appear to us as nothing but a fluttering of tiny wings, and might readily be described by an onlooker, ignorant of the previous history, as a game. In the case of the Warblers it is not probable that the conflicts often result in the death of one of the combatants, since their bills are not of the type that would easily inflict serious injury. The law of territory, moreover, does not demand that the struggles shall be fatal. That the weaker males shall be driven away and thus leave the stronger to reproduce in peace is all that is required. This law has but one end in view, namely, that the strength of the species shall at all costs be maintained, and if the conflicts were always, or in a large number of cases, to terminate fatally this end would not be attained. For since it can clearly not ordain which individual shall compete with which, since, in fact, the law of chance must here be relied upon, battles must frequently occur between two individuals both fit to reproduce; in which case the death of one member would be a loss, not a gain, to the species as a whole. If, therefore, the individuals of any one species were to develop such extraordinary pugnacity that surrender were out of the question, and a termination were only reached when one or the other succumbed to its injuries, that species would be at a disadvantage in the struggle for existence, and in the course of time would probably be eliminated. As it is, these contests do in the case of some species sometimes terminate fatally, and how easy it would be, if truly beneficial, for a species to arise with a motto of "no surrender" can be seen from the fact that man for his own amusement has in a comparatively short space of time been
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