BRITISH WARBLERS
season before commencing to breed? And is it not suggestive that breeding operations commenced so soon after the pool was discovered by the first individual? To Darwin it was somewhat of a mystery how it came about that within the same district during the height of the breeding season there should be so many males and females always ready to repair the loss of a mated bird, and in the "Descent of Man" he gives the results of experiments showing to what an amazing extent new mates will be forthcoming—results which from my own experience I believe to be in no degree exaggerated—and he considered that an explanation might be found in the fact that certain males and females do not succeed at the proper season in exciting one another's love, and consequently do not pair. Which are we then to believe— that males seek the females, or that the females seek the males? Or must we assume that a mutual search takes place, the sexes wandering about on the chance of ultimately discovering a suitable partner? No one who has studied the habits of the migratory species can seriously entertain this latter possibility, for whether the principle of breeding territory be accepted or not, this fact is patent, that the males settle and remain in a certain restricted area even before they are paired. Therefore if one sex does really seek the other, it can only be the females that seek the males. But since we see, on the one hand, a proportion of the males settling in their respective territories and there remaining, and since on the other we know that a proportion are wanderers with no fixed abode, and find that the males that remain in one place invariably secure a mate, while those that are wanderers appear to be always ready to pair when an opportunity arises, surely a more simple and more probable explanation of the fact that certain birds remain unpaired is afforded by the law of territory, the unpaired males being those which have been unsuccessful in securing a territory, the unpaired females those which have been unsuccessful in finding unpaired males in possession of a home. A curious feature with regard to the unpaired birds is
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