That birds exhibit pride might be considered doubtful if we had to rely only on the evidence supplied by the display of the peacock, and the strutting of the turkey-gobbler; for these actions, although so expressive of this emotion, may not really be due to it. But I think that the evident pleasure which is taken in achievement by talking birds can only be ascribed to the emotion in question. These birds regularly practise their art, and when a new phrase is perfected they show an unmistakable delight in displaying the result. Play is exhibited by many species in various ways, and it seems to be this class of feelings in their most organised form which have led to the extraordinary instincts of the bower-birds of New South Wales. The 'playhouses' of the animals have been described by Mr. Gould in his 'History of the Birds of New South Wales.' Of course the play-instincts are here united with those of courtship, which are of such general occurrence among birds; but I think no one can read Mr. Gould's description of the bowers and the uses to which they are put without feeling that the love of sportive play must have been joined with the sexual instincts in producing the result. But, be this as it may, there can be no question that these bowers are highly interesting structures, as furnishing the most unexceptionable evidence of true æsthetic, if not artistic feeling, on the part of the bird which constructs them; and, according to Mr. Herbert Spencer, the artistic feelings are physiologically allied with those of play. It is a matter of importance to obtain definite proof of an æsthetic sense in animals, because this constitutes the basis of Mr. Darwin's theory of sexual selection; but as he has treated the evidence on this subject in so exhaustive a manner, I shall not enter upon so wide a field further than to point out that the case of the bower-bird, even if it stood alone, would be amply sufficient to carry the general conclusion that some animals exhibit emotions of the beautiful. The following is Mr. Gould's description, _in extenso_, of the habits of the bird in question:--