look with some suspicion on the further extension of that system. It must be
remembered too that our commerce is not a purely natural growth. It has been
ever fostered by the legislature, and forced to an unnatural luxuriance by the
protection of our fleets and armies. The wisdom and the justice of this policy
have been already doubted. So soon, therefore, as it is seen that the further
extension of our manufactures and commerce would be an evil, the remedy is
not far to seek.
After six weeks' confinement to the house I was at length well, and could
resume my daily walks in the forest. I did not, however, find it so productive as
when I had first arrived at Dobbo. There was a damp stagnation about the paths,
and insects were very scarce. In some of my best collecting places I now found a
mass of rotting wood, mingled with young shoots, and overgrown with climbers,
yet I always managed to add something daily to my extensive collections. I one
day met with a curious example of failure of instinct, which, by showing it to be
fallible, renders it very doubtful whether it is anything more than hereditary
habit, dependent on delicate modifications of sensation. Some sailors cut down a
good-sized tree, and, as is always my practice, I visited it daily for some time in
search of insects. Among other beetles came swarms of the little cylindrical
woodborers (Platypus, Tesserocerus, &c.), and commenced making holes in the
bark. After a day or two I was surprised to find hundreds of them sticking in the
holes they had bored, and on examination discovered that the milky sap of the
tree was of the nature of gutta-percha, hardening rapidly on exposure to the air,
and glueing the little animals in self-dug graves. The habit of boring holes in
trees in which to deposit their eggs, was not accompanied by a sufficient
instinctive knowledge of which trees were suitable, and which destructive to
them. If, as is very probable, these trees have an attractive odour to certain
species of borers, it might very likely lead to their becoming extinct; while other
species, to whom the same odour was disagreeable, and who therefore avoided
the dangerous trees, would survive, and would be credited by us with an instinct,
whereas they would really be guided by a simple sensation.
Those curious little beetles, the Brenthidae, were very abundant in Aru. The
females have a pointed rostrum, with which they bore deep holes in the bark of
dead trees, often burying the rostrum up to the eyes, and in these holes deposit
their eggs. The males are larger, and have the rostrum dilated at the end, and
sometimes terminating in a good-sized pair of jaws. I once saw two males
fighting together; each had a fore-leg laid across the neck of the other, and the
rostrum bent quite in an attitude of defiance, and looking most ridiculous.
Another time, two were fighting for a female, who stood close by busy at her