35 
distinct looking insects were in reality only the sexes of the same 
species. This view soon became generally accepted, and they were 
treated as the sexes of one species, by Edward Doubleday, in his 
Genera of Lepidoptera , 1846. Later, however, specimens were sent 
from India, which closely resembled the male insect, P. pammon. 
This was supposed to overthrow the authority of Westerman’s obser¬ 
vation, and to re-establish P. polytes as distinct from P. pammon. 
This view of the matter was generally accepted, and the two appear as 
distinct species in the Catalogue of the Past India Museum, 1857, P. 
The notion of the male P. pammon having two distinct females, one 
somewhat similar in appearance to itself, the other so distinct as 
Linne’s P. polytes, did not appear to strike entomologists, until 
Wallace, in his paper on 4 The Papilionidse of the Malayan region ’ 
[Trans. Linn. Soc., 1865), stated that he felt convinced that this was so, 
because in every place where the male /’. pammon was found, a female 
resembling P. polytes was also found, and, further, although very much 
less frequently than on the Asiatic continent, a female closely 
resembling the male was also found. He further points out that not 
only has no male specimen of P. polytes yet been found, but that 
P. polytes itself has only been found in those localities in which P. 
pammon occurs. He concludes that, in this instance, varieties have 
been accepted as distinct species, and that the male P. pammon has 
two females, one similar to the male, the other, the insect described as 
distinct by Linne, and known as P. polytes. It may not be out of place 
here to note that Meldola [Studies in the theory of descent (translation), 
Weismann] has already suggested that the dimorphism and trimor¬ 
phism exhibited by certain butterflies has originated through poly¬ 
morphism from the ordinary variability of these species. Collections, 
however, brought from various parts of the East Indies, soon made us 
conversant with the fact, that, besides these two forms of the female, 
there were several others that might probably be referable to the same 
species, of which P. pammon represented the male form. These had 
been hitherto considered as distinct species under the names of theseus, 
polyphonies, antipints, melanides, alphenor, elyras, romulus, and ledebourius. 
Considerable variation exists in the length of the caudate appendages 
to the posterior wings, and, as Mr. Wallace pointed out, 4 Continental 
specimens have all considerably developed tails in both sexes.’ The 
insular specimens, on the other hand, which I treat as a separate 
species, have only a prominent tooth, or very short tooth in the male. 
Messrs. Godman and Salvin also describe the same character in 
Billiton specimens, in which the caudal appendage is slightly developed, 
and, in this respect, they agree best with Javan examples. I cannot, 
however, separate the continental and insular specimens as distinct 
species. My own collection contains examples from Banjarmassing, 
in which the males have these appendages well developed, whilst in 
other males from North Borneo they are almost extinct. We can, 
however, accept Wallace’s axiom in a general sense, and certify that 
insular specimens do, as a rule, vary from Continental ones more or 
less in this respect.” Dealing with the various forms, varieties, sub¬ 
species, etc., more in detail, Mr. Edwards said: 44 The typical male P. 
pammon has broad and rather short fore-wings, with ample hind- 
wings, which are dentated, and furnished with a spatulate tail. The 
wings are black, the fore-wings having a row of small white spots on 
