&c.), and commenced making holes in the hark. 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 Teally be guided by a simple sensation.
Those curious little beetles, the Brenthidse, werts 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 twro 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
boring. They pushed at each other with their rostra, and
clawed and thumped, apparently in the greatest rage,
although their coats of mail must have saved both from
injury. The small one, however, soon ran away, acknowledging
himself vanquished. In most Coleóptera the
m a l e b r e n t h h l e (Leptorhynchus angustatus) f i g h t i n g .
female is larger than the male, and it is therefore interesting,
as bearing on the question of sexual selection, that in
this case, as in the stag-beetles where the males fight
together, they should be not only better armed, but also
much larger than the females.
Just as we were going away, a handsome tree, allied to
Erythrina, was in blossom, showing its masses of large
crimson flowers scattered here and there about the forest.