then
loosely covers up the mouth of the hole, and is said by the natives to
obliterate and disguise its own footmarks leading to and from the hole,
by making many other tracks and scratches in the neighbourhood. It lays
its eggs only at night, and at Bouru a bird was caught early one morning
as it was coming out of its hole, in which several eggs were found. All
these birds seem to be semi-nocturnal, for their loud wailing cries may
be constantly heard late into the night and long before daybreak in the
morning. The eggs are all of a rusty red colour, and very large for the
size of the bird, being generally three or three and a quarter inches
long, by two or two and a quarter wide. They are very good eating, and
are much sought after by the natives.

Another large and extraordinary bird is the Cassowary, which inhabits
the island of Ceram only. It is a stout and strong bird, standing five
or six feet high, and covered with long coarse black hair-like feathers.
The head is ornamented with a large horny calque or helmet, and the bare
skin of the neck is conspicuous with bright blue and red colours. The
wings are quite absent, and are replaced by a group of horny black
spines like blunt porcupine quills.

These birds wander about the vast mountainous forests that cover the
island of Ceram, feeding chiefly on fallen fruits, and on insects or
crustacea. The female lays from three to five large and beautifully
shagreened green eggs upon a bed of leaves, the male and female sitting
upon them alternately for about a month. This bird is the helmeted
cassowary (Casuarius galeatus) of naturalists, and was for a long time
the only species known. Others have since been discovered in New Guinea,
New Britain, and North Australia.

It was in the Moluccas that I first discovered undoubted cases of
"mimicry" among birds, and these are so curious that I must briefly
describe them. It will be as well, however, first to explain what is
meant by mimicry in natural history. At page 205 of the first volume of
this work, I have described a butterfly which, when at rest, so closely
resembles a dead leaf, that it thereby escape the attacks of its
enemies. This is termed a "protective resemblance." If however the
butterfly, being itself savoury morsel to birds, had closely resembled
another butterfly which was disagreeable to birds, and therefore never
eaten by them, it would be as well protected as if it resembled a leaf;
and this is what has