454 Lieut.-Col. N, Manders on the Study of Mimicrif hy 



brown, or plain brown with yellow or white discal 

 band, to others with bluish white discal spots, and 

 red on the forewing. In Australia, very ranch the same 

 sequence is observed. It vaiies from a plain brown 

 butterfly with slight blue on the costa and disc, to a highly 

 variegated metallic red, white, and blue butterfly. We 

 can, in this extensive series, trace the gradual change from 

 a few scattered red scales, to a well-developed red band or 

 patch. 



There is an intimate relation between the colours brown 

 and blue in all butterflies. So far as ray own knowledge 

 extends, there is no blue butterfly in the world that, in 

 one or the other sex, has not sorae traces of brown. Blue, 

 if I may so express it, is a later colour than brown. It is 

 well exemplified in the European Lycaenidae. This being 

 so, we may consider ourselves justified in assuming that 

 the plain uniformly brown female represents the oldest 

 known form of that sex of holina at present existing. It 

 seems a natural conclusion that the uniformly coloured 

 inaria is also an older form, from which the more varie- 

 gated diocippus has been evolved. As in the case of 

 D. chrysippus, it is clear that it is not a sudden muta- 

 tion. 



Now as to the factor which has caused the resemblance 

 between the two species ; is it Natural Selection, or 

 what ? 



The argument for the former, that is, Mimicry, has been 

 elaborated by Prof. Poulton, in his well-known work, 

 "Essays on Evolution," and it is unnecessary to recapitu- 

 late or to discuss whether this is a case of Mltllerian or 

 Batesian mimicry. But further, there are the two forms 

 dorippus and cdcippus, which are also held to be due to 

 Natural Selection, and I will consider them fii'st. 



Danais chrysippus form doo'ippus. 



In the above Essays (p. 320), Prof. Poulton has put 

 forward the view that dorippus has been evolved from 

 chrysippus as a form of cryptic defence ; that is, though 

 it is an unpalatable insect, the struggle for existence is so 

 great in the desert areas in which it is usually found, that 

 it has been necessary for its survival to discard the con- 

 spicuous white band and black apex, and make itself as 

 near as may be to the colour of its environment. 



