But in the face of the facts before us this is just what we do not find. Among birds (who in erotic development far excel all other animals, not, indeed, excepting the human species, and thus must be accepted as affording the most perfect examples of sexual development) we have seen that the cases are not few in which the female equals, or even exceeds the male in size and in strength. This is so with the curlew, the merlin, the dunlin, the black-tailed goodwit, which is considerably larger than the male, and the osprey, where the female is also more spotted on the breast: these examples must be added to those I have already given (page 58). If we turn now to the beauty-test of brilliancy of plumage, we may observe an even larger number of examples of almost identical likeness between the sexes. Among British birds alone there are no fewer than 382 species, or sub-species,[83] in which the female closely resembles the male. In some few of these examples, it is true, the colours of the female are slightly duller, and in others the female is rather smaller than the male, but the difference in each case is very slight. It is specially significant to note that this similarity of plumage occurs in some of the most beautiful of our birds, as, for instance, the kingfisher and the jay, where the brilliant dresses of the sexes are practically alike; the female robin shares the beauty of the male; in all the families of the charming tits the sexes are alike; this is also the case with the roller-bird with its gaily-coloured plumage; and there is no difference between the white elegance of the female and the male swan. In the presence of such examples it seems to me impossible to refrain from thinking that there is a mistake somewhere, and that less importance is to be attached to the secondary sexual characters of the male than is generally imagined. Grant that these cases are exceptional; but if we once admit that among many species--and these highly developed in sex--the female shows no evidence of retarded development, we shall be forced also to break once for all with many beliefs and trite theories which have inspired on this subject of the sexual differences between the female and the male so much dogmatic statement and so many unproved assumptions.