8 MR. A. R. WALLACE ON THE PAPILIONIDÆ 
these two groups of Papilio, and I am disposed to believe that we have here 8 case of 
mimicry, brought about by the same causes which Mr. Bates has so well explained in his 
account of Heliconidæ, and which thus led to the singular exuberance of polymorphic 
forms in this and allied groups of the genus Papilio. I shall have to devote a section of - 
my paper to the consideration of this subject. — 
The third example of polymorphism I have to bring forward is Papilio Ormenus, 
Guér., which is closely allied to the well-known P. Erechtheus, Don., of Australia. The 
most common form of the female also resembles that of P. Erechtheus; but a totally 
different-looking insect was found by myself in the Aru Islands, and figured by Mr. 
Hewitson under the name of P. Onesimus, which subsequent observation has convinced 
me is a second form of the female of P. Ormenus. Comparison of this with Boisduval's 
description of P. Amanga, a specimen of which from New Guinea is in the Paris 
Museum, shows the latter to be a closely similar form; and two other specimens were 
obtained by myself, one in the island of Goram and the other in Waigiou, all evidently 
local modifieations of the same form. In each of these localities males and ordinary 
females of P. Ormenus were also found. So far there is no evidence that these light- 
coloured insects are not females of a distinct species, the males of which have not been . 
discovered. But two facts have convinced me this is not the case. At Dorey, in New 
Guinea, where males and ordinary females closely allied to P. Ormenus occur (but which 
seem to me worthy of being separated as a distinct species), I found one of these light- 
coloured females closely followed in her flight by three males, exactly in the same manner 
as occurs (and, I believe, occurs only) with the sexes of the same species. After watching 
them a considerable time, I captured the whole of them, and became satisfied that I 
had discovered the true relations of this anomalous form. The next year I had corro- 
borative proof of the correctness of this opinion by the discovery in the island of Bat- 
chian of a new Species allied to P. Ormenus, all the females of which, either seen or 
captured by me, were of one form, and much more closely resembling the abnormal 
light-coloured females of P. Ormenus and P. Pandion than the ordinary specimens of 
that sex. Every naturalist will, I think, agree that this is strongly confirmative of the 
supposition that both forms of female are of one species; and when we consider, further, 
that in four separate islands, in each of which I resided for several months, the two forms 
of female were obtained and only one form of male ever seen, and that about the same 
time M. Montrouzier in Woodlark Island, at the other extremity of New Guinea (where 
he resided several years, and must have obtained all the large Lepidoptera of the island), 
obtained females closely resembling mine, which, in despair at finding no appropriate 
partners for them, he mates with a widely different species,—it becomes, I think, 
NE evident that this is another case of polymorphism of the same nature as 
rent pointed out in P. Pammon and P. Memnon. This species, however, is 
tenai suite a but trimorphic; for, in the island of Waigiou, I obtained a third 
on iim: "s ees saine the others, and in some degree intermediate between 
re Ame P E The specimen ıs particularly interesting to those 
produced by what hai Bul Bone Papi of the sexes has been gradually 
f erms sexual selection, since it may be supposed to exhibit one of 
t 
