maximum, at least in Europe, in the blackcock and capercailzie. I have myself seen both these birds exhibiting to the females, in Norway. The cock-of-the-rock offers another striking example of the importance of courtship amongst birds. The male of this species is, from beak to tail, of a deep orange, or, more beautiful still, of a brilliant blood-red colour. From the beak one may well say, for this, to the very tip, as well as the head itself, is covered with, or rather buried in, a magnificent crescent-shaped crest, which, by obscuring the usual contour of that region, gives a touch of _bizarrerie_ to a _tout ensemble_ sufficiently splendid. As in the case of the argus pheasant, a little open space is selected, the mossy turf of which soon becomes pressed smooth by the tramplings of the birds’ feet. In it the adorned males, to the admiration of their more sombre-coloured lady-loves, dance and spring about, engaging, from time to time, in fierce and valorous conflicts. Whilst not in the ring, as one may say, the birds often fly from one to another of the neighbouring trees, to the trunks of which they sometimes cling, all in the greatest excitement. As in all other cases of the sort, the females are supposed to accept, by preference, those males for their husbands, whose plumage, when thus shown to advantage, creates the most dazzling effect. This is the theory of sexual selection by which Darwin accounts for most of the very beautiful colours and markings throughout nature. But though his arguments have never been shaken, whilst the evidence on which they are based has been most effectively supplemented,[3] yet naturalists, as a body, seem determined to ignore both the one and the other, and to see in the most striking patterns and conspicuous hues, a “protective resemblance” to the surrounding landscape, which, if it really exist for any man, must be due rather to some personal cause, such as strong imagination or weak eyesight—or a combination of the two—than to any objective reality. There is no animal now, in fact, however conspicuous it may be to the eye of the savage, that is not pronounced almost invisible by some spectacled old gentleman or another, and I feel confident myself that, were a red or blue lion to step off a public-house and walk in full view down the street, it would be thought to “blend wonderfully” with the houses on either side, by these thorough going advocates of the protective theory. Darwin, however, who has pointed out so many cases of assimilative colouring, all of which are accounted for on his theory of natural selection, did not believe that the tiger or zebra were protected in this way, nor would he, probably, have endorsed the red lion.