Dec. 31, 1909. The Queensland Naturalist. 93 
striking than the accurate manner in which some African 
species'^ imitate the striped and spotted Acreae, which 
inhabits the same districts.* 
There seems to be some dinerence of opinion as to the 
origin of such variation of form and colour between^ the 
sexes of these butterflies. In larger animals, and birds, 
etc., such differences are said to be due to the law of 
Sexual Selection, “ which depends.” says Darwin, “ not on 
a struggle for existence, but on a struggle betw^een the 
males for possession of the females ” ; he tells us also that 
in many cases victory depends, not on a general vigour, 
but on having special w^eapons confined to the male sex.”f 
In the case of Lepidopterous insects, how’ever, such 
variations are probably more often due to other causes, 
and w'e may reasonably suppose that the greater import- 
ance of the female insect, her usually wnaker flight, 
and larger size, demanded special protection, and that 
during a long struggle for existence any variations of colour 
proving advantageous to the species that might have 
liappened to appear, would, by the law^ of Natural Selection, 
have been perpetuated, and gradually have become more 
and more pronounced. In support of this view' of the 
matter, w'e often find that where direct protection of any 
kind is present in a species, the sexes are alike : as in the 
Danaidae and Heliconidae, that are disagreeable in flavour. 
Stinging hymenoptera, too, with the exception of some of 
the Humble bees, appear to have the sexes coloured 
similarly. 
On the other hand, it seems probable that the sexual 
differences of some Coleopterous and Orthopterous insects 
are due to Sexual Selections ; and Darwin tells us that 
the male beetles of various kinds of Lucanidae often bear 
wounds from the huge mandibles of other males. 
Swinton also inclines to this vicAV, and observes that 
“ the battle of male for the female that burns so fiercely 
in higher organizations, wiiich gave antlers to the stag, 
horns to the bull, spurs to the cock, and incisive weapons 
to the fish, smoulders yet more intensely in mandibulate 
insects of the Orthoptera Coleoptera. Hymenoptera, and 
Neuroptera, many of whom bite and devour one another.” 
It is my purpose, how^ever. to notice more X3articularly 
the effects of Protective Colouring with respect to lepidop- 
terous insects, and perhaps a few' preliminary remarks on 
its occurence during their larval stage may be considered 
of interest. 
Soft-bodied caterpillars, Avhich are especially defence- 
less, are usually green w^hen just hatched, like the colour 
of the leaves on which they live ; but after a few moults 
* Wallace. — Trans. Ent. Soc., Lond., 1869. 
f Darwin. — Otigin of Species, Chap, 4, p. 42. 
