74 
NATURAL SELECTION 
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usually olive-green or brown ; and in several cases these most 
curiously resemble the Tropidorhynchus of the same island. 
For example, in the island of Bouru is found the Tropido- 
rhynchus bouruensis, of a dull earthy colour, and the Mimeta 
bouruensis, which resembles it in the following particulars : 
The upper and under surfaces of the two birds are exactly of 
the same tints of dark and light brown ; the Tropidorhynchus 
has a large, bare black patch round the eyes ; this is copied 
in the Mimeta by a patch of black feathers. The top of 
the head of the Tropidorhynchus has a scaly appearance, from 
the narrow scale-formed feathers, which are imitated by the 
broader feathers of the Mimeta having a dusky line down 
each. The Tropidorhynchus has a pale ruff formed of curious 
recurved feathers on the nape (which has given the whole genus 
the name of Friar birds) ; this is represented in the Mimeta 
by a pale band in the same position. Lastly, the bill of the 
Tropidorhynchus is raised into a protuberant keel at the base, 
and the Mimeta has the same character, although it is not a 
common one in the genus. The result is, that on a super- 
ficial examination the birds are identical, although they have 
important structural differences, and cannot be placed near 
each other in any natural arrangement. As a proof that the 
resemblance is really deceptive, it may be mentioned that the 
Mimeta is figured and described as a honeysucker in the costly 
Voyage de l’ Astrolabe, under the name of Philedon bouruensis ! 
Passing to the island of Ceram, we find allied species of 
both genera. The Tropidorhynchus subcornutus is of an earthy 
brown colour washed with yellow ochre, with bare orbits, 
dusky cheeks, and the usual pale recurved nape-ruff. The 
Mimeta forsteni is absolutely identical in the tints of every 
part of the body, the details of which are imitated in the 
same manner as in the Bouru birds already described. In 
two other islands there is an approximation towards mimicry, 
although it is not so perfect as in the two preceding cases. 
In Timor the Tropidorhynchus timoriensis is of the usual 
earthy brown above, with the nape-ruff very prominent, the 
cheeks black, the throat nearly white, and the whole under 
surface pale whitish brown. These various tints are all well 
reproduced in Mimeta virescens, the chief want of exact imita- 
tion being that the throat and breast of the Tropidorhynchus 
