WCP2977

[1]

ZOOLOGICAL MUSEUM,

TRING

HERTS, ENGLAND.

Feburary 23rd 1910

Dear Dr Wallace

The changing glow which you refer in your letter of Febr. 18th is only found in a limited number of species. It is found in a number of species of Papilio allied to aristodemus [?] of which autora Bray in the Amazon from the ♂, for instance in eulaces Gray, phosphorus Bates, lycimenes Boisd [2] polygelus Feld, anchises, d., and others. When viewed obliquely, the black hindwing changes into metallic blue, which, I think, is the cause of these appearing a peculiar lustre above the "opalescent" spots. In this case the spots would be best designated as phosphorescent, I think Ornithoptera magellanus Feld. (Philippines) has a similar lustre, but the wings resembles were more a polished opal than phosphorus, these being no luminous aloud [?] above the surface of the wing.

The eugcimid Euselasia praeclara [3] Hew., from the Amazon, has the strangest glow of all Lepidoptera. Here the gloss is a buffish yellow surface and therefore appears some what raised above the wing, but I should call it opalescent rather than phosphorescent.

Burgena chalybeata Roth., an Agaristid from the Bismarck Archipelago, may also be mentioned. Both its wings change on the upperside from black to blue, fiery red and opalescent. The change observed in Spatuna [?] iris is quite common among butterflies. [4] I do not think that any researches have been published on the luminous sheen of these insects.

Believe me, | very faithfully yours | K. Jordan¹ [signature]