Again, Mr. Wallace[71] tells us of no less than four kinds of orioles, which birds mimic, more or less, four species of a genus of honey-suckers, the weak orioles finding their profit in being mistaken by certain birds of prey for the strong, active, and gregarious honey-suckers. Now, many other birds would be benefited by similar mimicry, which is none the less confined, in this part of the world, to the oriole genus. It is true that the absence of mimicry in other forms may be explained by their possessing some other (as yet unobserved) means of preservation. But it is nevertheless remarkable, not so much that one species should mimic, as that no less than four should do so in different ways and degrees, all these{91} four belonging to _one and the same genus_. [Illustration: THE LONG-TAILED BIRD OF PARADISE.] In other cases, however, there is not even the help of protective action to account for the phenomenon. Thus we have the wonderful birds of Paradise,[72] which agree in developing plumage unequalled in beauty, but a beauty which, as to details, is of different kinds, and produced in different ways in different species. To develop "beauty and singularity of plumage" is a character of the group, but not of any one definite kind, to be explained merely by inheritance. {92} [Illustration] Again, we have the very curious horned flies,[73] which agree indeed in a common peculiarity, but in one singularly different in detail, in different species and not known to have any protecting effect. Amongst plants, also, we meet with the same peculiarity. The great group of Orchids presents a number of species which offer strange and bizarre {93} approximations to different animal forms, and which have often the appearance of cases of mimicry, as it were in an incipient stage. [Illustration: HORNED FLIES.] [Illustration: THE MAGNIFICENT BIRD OF PARADISE.] The number of similar instances which could be brought forward from amongst animals and plants is very great, but the examples given are, it is {94} hoped, amply sufficient to point towards the conclusion which other facts will, it is thought, establish, viz. that there are causes operating (in the evocation of these harmonious diverging resemblances) other than "Natural Selection," or heredity, and other even than merely geographical, climatal, or any simply external conditions.