production of resemblance in allied species of Butterflies. 421 
unobserved immigration over such an immensearea is highly 
improbable. 
It is now many years ago since he, either in a letter or 
in conversation, remarked to me that a butterfly with a deep 
blue-glossed wing is almost a sure indication of a habitat 
of deep jungle, great moisture and intense heat, and I have 
no doubt that in very many instances he is correct. In 
such a climate as the above, in the Khasia Hills, Assam, 
where the rainfall sometimes exceeds three hundred inches, 
the blue gloss on this otherwise brown butterfly is induced ; 
in Maldah, where the country is more open, the rainfall less 
heavy but still abundant, and the heat very great, the blue 
gradually disappears ; in Ceylon, where the climate varies 
again in the direction of lesser heat and rainfall, the 
blue entirely disappears, but the heat and rainfall are 
sufficiently great to prevent the spots, now deprived of their 
blue, from becoming conspicuous. On the western side of 
the Ghats m South India neither the heat, rainfall nor 
moisture is so great as in Ceylon, and consequently the spots 
on both fore and hind wing become white and prominent. 
This applies equally to the case of the more restricted 
E. coreta. In £. core the same applies, but in the Punjab 
with its scanty rainfall, dry heat and absence of forest, and 
in the lower ranges of the N.W. Himalayas, where there 
are several degrees of frost in the cold weather, the white 
spots become large and prominent, giving the insect a 
well-marked and distinctive appearance. 
That climate is the main factor in the production of 
this so-called Miillerian combination can be further 
demonstrated experimentally, for if we take the newly- 
formed pupa of the Ceylon form of £. cove, which, as I have 
said, never has pure white spots on the forewing, and 
subject it to the same climatic conditions as obtain in the 
Nilgiris, we can produce a butterfly indistinguishable from 
certain Nilgiri specimens. Want of material has up to 
the present prevented me from experimenting with the 
pupae of the two other species, but I have no doubt they 
would follow the same lines. 
I now turn to the discussion of a Miillerian combination 
of Danaines (Amauris) in South Africa. It is to be found 
in a paper by Mr. 8S. A. Neave in our Transactions for 
1906, entitled “Some bionomic notes on Butterflies from 
the Victoria Nyanza,” under the sub-heading “ Association 
of Amauris echeria jacksoni, Sharp, and A. albimaculata, 
