MIMICRY 573 



in a paper that will always be classical (Trans. Linn. Soc. xxiii. pp. 

 495-566, pis. 55, 56). The explanation is simply that the weaker 

 animal, or that which exists under less favourable conditions, 

 " mimics '' the stronger, or that which is more flourishing, the 

 Mimicry being presumably effected by means of Natural Selection ; 

 but the difficulties which attend the investigation of the way in 

 which this result is brought about, so as to render the explanation 

 in all cases acceptable, are often extremely gi'eat, and one ought 

 not to be surprised that some zoologists are unable to accept this 

 explanation at all. Indeed it is only by fully appreciating the 

 enormous advantage which protective coloration confers upon 

 certain forms of animal life that any zoologist can bring himself to 

 believe that changes so great, and deviation from the usual appear- 

 ance of kindred forms so extensive, can be produced in the manner 

 indicated. The difficulties seem also to be increased by the fact 

 that instances of Mimicry, though not unfrequent, and found in 

 many widely differing groups, do not occur oftener ! 



Cases strictly analogous to those so admirably treated by the 

 late Mr. Bates were immediately after described by Mr. Wallace 

 {Proc. Zool. Soc. 1863, pp. 26-28) as existing in Birds, and especially 

 in certain species of the genus or subgenus known as Mimeta ^ 

 (Oriole) which inhabit many of the islands of the Malay Archi- 

 pelago, and so nearly resemble those of the genus Philemon'^ 

 (Friar-bird) inhabiting the same islands as to deceive even some 

 of the most expert ornithologists.^ The details have since been 

 more or less fully given by him in several accessible works {Malay 

 Archipelago, ii. chap, xxvii. ; Contrib. Theory Nat. Selection, pp. 103- 

 106 ; Darwinism., pp. 262-264), so that there is no need here to dwell 

 upon them. It will be enough to state that the two species of 

 Mimeta, M. hourouensis and M. forsteni, respectively inhabiting the' 

 islands of Bouru and Ceram, are on superficial examination identical 

 in appearance with two species of Philemon, P. moluccensis or 

 hourouensis and P. subcornntus, natives of the same islands, the 

 Oriole and Friar-bird of each island respectively presenting exactly 

 the same tints — the black patch of bare skin round the eyes of the 

 latter, for instance, being counterfeited in the former by a patch 



^ It is a curious fact that this genus was, in 1827, named Mwietes (that is, 

 Mimic) by Capt. Philip King {Survey &c. of Australia, ii. pp. 417, 418) under 

 the belief that the birds composing it belonged to the Family Melipliagidee, 

 which had assumed the appearance of Orioles, whereas the imitation, as will be 

 seen by the text, is just the other way ! 



- Tropiclo7-hynchus Mr. Wallace calls it, but Philemon is the older name. 



^ These of course have judged from external appearance only. By any one' 

 with the opportunity of examining the tongue no mistake should be possible, 

 for that member in the Mcliphagidse, (Honey-eater) to which Philemon or 

 Tropidorhynchus belongs, is most characteristic. 



