would be as well protected as if it resembled a leaf; and this is what has been
happily termed "mimicry" by Mr. Bates, who first discovered the object of these
curious external imitations of one insect by another belonging to a distinct genus
or family, and sometimes even to a distinct order. The clear-winged moth which
resemble wasps and hornets are the best examples of "mimicry" in our own
country.
For a long time all the known cases of exact resemblance of one creature to
quite a different one were confined to insects, and it was therefore with great
pleasure that I discovered in the island of Bouru two birds which I constantly
mistook for each other, and which yet belonged to two distinct and somewhat
distant families. One of these is a honeysucker named Tropidorhynchus
bouruensis, and the other a kind of oriole, which has been called Mimeta
bouruensis. The oriole resembles the honeysucker 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 superficial examination the birds are
identical, although they leave important structural differences, and cannot be
placed near each other in any natural arrangement.
In the adjacent island of Ceram we find very distinct species of both these
genera, and, strange to say, these resemble each other quite as closely as do
those of Bouru The Tropidorhynchus subcornutus is of an earthy brown colour,
washed with ochreish yellow, with bare orbits, dusky: cheeks, and the usual
recurved nape-ruff: The Mimeta forsteni which accompanies it, is absolutely
identical in the tints of every part of the body, and the details are copied just as
minutely as in the former species.
We have two kinds of evidence to tell us which bird in this case is the model,
and which the copy. The honeysuckers are coloured in a manner which is very
general in the whole family to which they belong, while the orioles seem to have
departed from the gay yellow tints so common among their allies. We should
therefore conclude that it is the latter who mimic the former. If so, however, they