202 TRAIJSACTIONS OF SECTION D. 



in several cases seem to mimic those of the genus Delias, and that ' in all cases 

 the pairs "which resemble each other inhabit the same district, and very often are 

 known to come from the same locality.' The parallelism is even stronger than 

 was stated by Wallace, for there is not a single known member of the genus 

 Prioneris which does not resemble a species of Delias, so that Prioneris cannot 

 really be said to have an aspect of its own. Prioneris clemanthe and Delias 

 agostina form a pair inhabiting the Himalayas, Burma and Further India. In 

 the same region occur Prioneris thestylis and Delias belladonna, the striking 

 similarity of which species, especially on the underside and in the female, drew 

 the special attention of Mr. Wallace. A still more remarkable instance is that 

 of Prioneris sita of southern India and Ceylon, the likeness of which to the 

 common Indian Delias eucharis is spoken of by Wallace as ' perfect ' ; while 

 Fruhstorfer, a hostile witness, testifies to the fact that the Prioneris always flies 

 in company with the Delias, and rests just like the latter with closed wings on 

 the red flowers of the Lantana. Prioneris hypsipyle of Sumatra and P. autothishe 

 of Java are like Delias egialea and D. crithoe of the same two islands. Here 

 again Fruhstorfer says of Prioneris autothishe, that it visits the flowers of the 

 Cinchona, 'always in company with the similarly coloured Delias crithoe.' 

 Wallace remarked on the close similarity between Prioneris Cornelia of Borneo 

 and Delias singhapura of the Malay Peninsula ; in this case, it will be noted, the 

 localities though not far distant from each other, are not identical. But a 

 Delias form which was unknown at the date of Wallace's paper has since been 

 found in Borneo, and this latter butterfly, known as D. indistincta, is even more 

 exactly copied by P. Cornelia than is the Delias which first drew Wallace's 

 attention. Prioneris vollenhovii of Borneo is a kind of compromise between 

 Delias indistincta and, on the underside, D. jxinde?nia of the same island; and 

 it may be added that another Bornean Pierine, Huphina pactolica, is a good copy 

 of Delias indistincta, therefore resembling also the Bornean Prioneris cornelia 

 and P. vollenhovii. 



The memoir, published in 1867, in which Wallace remarked on the parallelism 

 between Prioneris and Delias, contains a noteworthy prediction by the same 

 author. Speaking of Pieris (now called Huphina) laeta of Timor he says that 

 it ' departs so much from the style of colouring of its allies and approaches so 

 nearly to that of Thyca [Delias] belisama of Java, that I should almost look 

 foran ally of the last species to be discovered in Timor to serve as its pattern.' 

 Thirty-four years after the expression of this anticipation, Mr. Doherty dis- 

 covered in Timor an ally of Delias belisama which at once suggests itself as the 

 model from which the peculiar and brilliant colouring of Hvphina laeta has 

 been derived. Fruhstorfer, who is by no means friendly to the theory of 

 mimicry, says of this Delias, which was named splendida by Lord Rothschild, 

 that beneath it is ' deceptively like Huphina laeta.' But here comes in a curious 

 point. The black forewing with its yellow apex and the orange-yellow hindwing 

 with its scarlet black-bordered costal streak are present on the underside of 

 both the Delias and the Huphina; but the latter butterfly possesses in addition 

 to these features a row of scarlet marginal spots on the hindvring which are 

 not to be found on the Delias. In spite of this discrepancy, the likeness is 

 sufficiently striking. But from the same island of Timor, Doherty sent home 

 another Delias which besides resembling D. splendida, possesses a row of 

 scarlet patches in the corresponding situation to those of H. laeta. In this 

 latter Delias, however, named dohertyi by Lord Rothschild after its discoverer, 

 the brilliant scarlet costal streak is completely absent. The Huphina, there- 

 fore, is more like either species of Delias than they are like each other, forming, 

 as it were, a link between them. So that, adopting Professor Poulton's 

 terminology, we may say that, if this is a case of mimicry, one form may possess 

 at the same time the aposemes belonging to two distinct models. I will not now 

 stop to discuss the bearing of this case on current theories, but will only remark 

 that, granting mimicry, the whole assemblage, D. splendida, H. laeta, D. 

 dohertyi. may be expected to gain advantage from the blending action of the 

 intermediate H. laeta. This I think would happen whether laeta is a ' Batesian ' 

 or ' Miillerian ' mimic, but the gain to the association in the latter case is 

 certainly the more obvious. 



This state of things would be sufficiently curious if it stood by itself. But it 



