22 MR. A. R. WALLACE ON THE PAPILIONIDÆ 
P. Coon, but with red instead of yellow spots (P. Doubledayi, Wall.), the corresponding 
variety of P. Androgeus (P. Achates, Cram., 182, A,B,) has acquired exactly the same 
peculiarity of having red spots instead of yellow. Lastly, in the island of Timor, the 
female of P. Œnomaus (a species allied to P. Memnon) resembles so closely P. Liris 
(one of the Polydorus-group), that the two, which were often seen flying together, could 
only be distinguished by a minute comparison after being captured. 
The last six cases of mimiery.are especially instructive, because they seem to indicate 
one of the processes by which dimorphie forms have been produced. When, as in these 
cases, one sex differs much from the other, and varies greatly itself, it may happen that 
occasionally individual.variations will occur having a distant resemblance to groups which 
are the objects of mimicry, and which it is therefore advantageous to resemble. Such 
a variety will have a better chance of preservation; the individuals possessing it will be 
multiplied ; and their accidental likeness to the favoured group will be rendered perma- 
nent by hereditary transmission, and, each successive variation which increases the re- 
semblance being preserved, and all variations departing from the favoured type having 
less chance of preservation, there will in time result those singular cases of two or more | 
isolated and fixed forms bound together by that intimate relationship which constitutes 
them the sexes of a single species. The reason why the females are more subject to this 
kind of modifieation than the males is, probably, that their slower flight, when laden 
with eggs, and their exposure to attack while in the act of depositing their eggs upon 
leaves, render it especially advantageous for them to have some additional protection. 
This they at once obtain by acquiring a resemblance to other species which, from what- - 
ever cause, enjoy a comparative immunity from persecution. I 
` This summary of the more interesting phenomena of variation presented by the eastern - 
Papilionidz is, I think, sufficient to substantiate my position, that the Lepidoptera are | 
` a group that offer especial facilities for such inquiries; and it will also show that they | 
have undergone an amount of special adaptive modification rarely equalled among the — 
the more highly organized animals. And, among the Lepidoptera, the great and pre- | 
eminently tropical families of Papilionidæ and Danaidæ seem to be those in which com- 1 
plicated adaptations to the surrounding organic and inorganic universe have been most 1 
completely developed, offering in this respect a striking analogy to the equally extraor- : 
dinary, though totally different, adaptations which present themselves in the Orchidee, T 
the only family of plants in which mimiery of other organisms appears to play any im- H 
portant part, and the only one in which striking cases of polymorphism occur; for such … 
MEL ue cen. os and hermaphrodite forms of Catasetum tri- ; 
E y in form and structure that they were long considered — 
to belong to three distinct genera. 
Arrangement and. Geographical Distribution of the Malayan Papilionidæ. 
en: of Papilionide inhabiting the Malayan region are very numerous, 1 | 
PA ne d ee out of the nine genera into which the family is divided. One of | 
Face Me ei is restricted to Australia, and another (Teinopalpus)to the . 
dro PN » While no less than four (Parnassius, Doritis, Thais, and Sericinus) — 
o Southern Europe and to the mountain-ranges of the Palæarctic region. 
nn 
