THE YOUNG NATURALIST. 



251 



NOTES ON INTERMEDIATE VARIETIES 

 OF LEPIDOPTEROUS INSECTS. 



By C. S. GREGSON. 



In Mr. Robson's interesting paper on this subject {Young Naturalist, page 

 209) certain startling suggestions are worked out to bis satisfaction, but as 

 I fear the facts are against his line of argument, I think it will be quite 

 logical if I recapitulate some of the facts that our young friends may not be 

 led into error. Many years ago, a then leading member of the " Entomo- 

 logical Society," of London, having received black varieties of A. ietularia 

 from me, now known as " Doubledayaria" exhibited them at a meeting of the 

 Society, observing there were no intermediate varieties, and to that little 

 observation, published in our magazines next month, may be traced 

 the whole of the assertions which have so often cropped up : " There 

 are no intermediate varieties." I pass by the quotation from Lord Walsing- 

 ham's speculations as the cause of dark coloured insects in high latitudes, 

 because I have never seen his paper; and I shall not follow Mr. 

 Robson's interesting paper, but at once write out a number of species 

 -—African and British — from my own knowledge, so that the readers 

 may judge for themselves as to whether there are species which produce 

 intermediate varieties or not. I shall be exceedingly pleased to hear from 

 as many of the readers as possible what species other than those I shall 

 name, they know to have intermediate varieties. The species I shall name 

 have all intermediate varieties in my own collection, and in some cases I 

 possess long series of such. 



AFRICAN INTERMEDIATE VARIETIES. 



Diadema chrysippus, from Natal, South Africa, is small and dark, like 

 European ; from Cameroons, West Africa, it is large and light coloured, vary- 

 from variety missippus and semialha with dusky to light whitish underwings, 

 to variety alba with pure white underwings, except only the central spot and 

 marginal band. All these forms I have seen annually, thus they are repro- 

 duced intermediate varieties. 



Papillio mecrope, known as P. hypocoon, varies from rich dark brown and 

 white, to rich brown and ochre. In West Africa the form is generally the 

 first, sometimes the underwings are slightly rayed with ochreous ; whilst in 

 South Africa the ochreous colours are intensified, and in a series many inter- 

 mediate forms occur. Again, in the genus Harma, male specimens from 

 Cameroons and from the mainland vary so much that I have repeatedly 

 thought them different species until I got intermediate varieties. 



