GRASSHOPPER-WARBLER
such a supposition, be led to assume that colour was solely dependent upon and inseparable from vigour; thus the necessity for calling in such remote possibilities as aesthetic sense and selection in explanation of the phenomenon would be removed.
Let us compare the courtship of the famous Argus Pheasant with that of any of the dull-coloured Warblers, for instance, Savi's Warbler (Locustella luscinioides). Here we have two cases, extreme as regards development of colour and shading, yet analogous in all other respects. The Argus Pheasant, when in presence of the female, spreads out and raises its tail and wings, the ocelli on the latter being thereby fully displayed; Savi's Warbler also under similar circumstances spreads out his tail and wings, the latter being very slowly waved up and down. These actions are identical, and evidently spring from the same cause, but no one can say that Savi's Warbler, in thus performing, has any special beauty to display. If, then, we say that the Argus Pheasant is conscious of the ocelli, of what is Savi's Warbler conscious? Clearly we are no more justified in imputing consciousness to the actions in the one case any more than we are in those of the other.
The courtship of birds presents many curious features; none more so than the spreading out of the wings and tail, commonly known as display, but these actions are not confined solely to courtship.
I have described the males of the species under consideration, both when playing with one another prior to the arrival of the females, and when feeding their fully fledged young, as behaving in an exactly similar manner. The male Chiffchaff, before the arrival of the female sometimes seems to be seized with a sudden ecstasy. He spreads his tail and jerks his wings, singing to himself quickly and quietly; also when a hawk approaches his breeding-quarters too closely he will fly into the air, slowly flapping his wings, and hurriedly singing in a similar manner to his courtship. I will give one other
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