MIMICRY 573 
in a paper that will always be classical (Trans. Linn. Soc. xxiii. pp. 
495-566, pls. 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 great, 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. bourouensis 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 
bourouensis and P. subcornutus, 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 
1 It is a curious fact that this genus was, in 1827, named Mimetes (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 Meliphagidz, 
which had assumed the appearance of Orioles, whereas the imitation, as will be 
seen by the text, is just the other way ! 
2 Tropidorhynchus Mr. Wallace calls it, but Philemon is the older name. 
8 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 Meliphagidw (Honry-bATER) to which Philemon or 
Tropidorhynchus belongs, is most characteristic. 
