(_a_) The harmless Indian Snake (_Lycodon aulicus_) is closely similar to the well-known Krait (_Bungarus cœruleus_), also Indian; but the resemblance extends to a structural detail which can hardly have mimetic value—namely, the harmless snake has long, fang-like front teeth, though these are unconnected with poison-glands. Animals which come into contact with the krait and its mimic are hardly likely to inspect their teeth. (_b_) A considerable number of birds of the shrike group—known as Cuckoo-Shrikes (_Campophaga_)—closely resemble cuckoos in plumage; but even if they derive any benefit from mimicking birds which are credited with being mimics already, they cannot profit by the fact that the shafts of the rump-feathers in both groups are stiffened; this being a peculiarity which would not be perceptible until the bird was in the grasp of an aggressor. (_c_) As a third case of coincidence we may refer to the tubercle in the nostril of the Brain-fever-bird (_Hierococcyx varius_), as a minute detail of hawk-like appearance, though not present in the particular species imitated. 6. The argument that mimetic resemblances are produced in the most diverse ways, but the result is uniform, loses much of its force when we consider the various methods by which short-tailed birds appear to have long caudal appendages. In the peacock it is the upper tail coverts which are elongated; in the Stanley Crane (_Tetrapteryx paradisea_) it is the innermost or tertiary quills of wing; in one of the egrets some of the feathers of the upper back grow to a great length and form a train; in the Bird of Paradise (_Paradisea apoda_) the long flank plumes are commonly mistaken for the tail. In these cases there can be no question of mimicry. 7. We have shown that the idea that imitator and imitated are always found in the same area is absolutely fallacious. In birds, for example, the most striking resemblances appear to occur between species that dwell far apart. 8. We can cite, as parallel to the case of a mimicking species of which the male copies one model and the female another, the strange similarity between the barred brown plumage of the female blackcock and that of the female eider-duck. The males of these species, although both black and white, differ greatly in appearance; but the male blackcock is admittedly very like the male of another species of sea-duck—the scoter. 9. Against the supposed ancestral non-mimetic forms existing on islands we can pit the “mimetic” orioles in small islands and their non-mimetic cousins on the mainland. In Australia an oriole of what appears to be an ancestral style lives beside, but declines to mimic, a friar bird of a very pronounced type.