200 THE ENTOMOLOGIST. 



has been tried in this country, nor with what success, although, 

 from the above facts being well known to our English Lepi- 

 dopterists, it seems almost a foregone conclusion that the 

 experiment has been tried." About the first week in June I 

 planted a young cabbage in a pot, and taking a couple of 

 females that were depositing their eggs placed them all 

 under a bell-glass. They laid about thirty eggs; and after a 

 week had elapsed I examined them every morning for the 

 hatching of the larva3, which appeared on the 18th. I then 

 removed half and placed them upon a mignonette plant, also 

 in a pot; these I bred under a bell-glass in the shade of a 

 tree in the garden. The other half were left on the plant and 

 placed in a hothouse, where the temperature was 65° to TC, 

 rising to 80"^ by day, and 85° when the sun shone : they 

 changed to pupae from the 30th of June to the 3rd of July, 

 and emerged as perfect insects from the 9th to the 13th of July, 

 The others, fed out of doors, were exactly a week later in 

 changing to pupae, and came out from the 18th to the 21st. 

 Now for the results. I could not perceive any difference in 

 colour between those fed upon mignonette and the others 

 fed in heat: they were all the ordinary form of P. Rapa) ; 

 therefore it seems improbable that the food has anytiiing to 

 do with the change, as mine never tasted anything but 

 mignonette from the day they were hatched. Now, it is well 

 known that the variety of Gonepteryx Rhamni called 

 Cleopatra, in which the orange spot on the upper wing is so 

 enlarged as to be spread over nearly the whole of it, is found 

 only in the south of Europe, and especially on the shores of 

 the Mediterranean ; and 1 think probably the yellow variety 

 of P. Rapae proceeds from the same cause, and is only 

 another instance of the effect of increased warmth of climate 

 in intensifying colour. Perhaps the failure of my experiments 

 was due to my not having sufficient heat at command, as it 

 was nothing like the temperature of some parts of North 

 America. Mr. Cmtis, in his 'Farm Insects,' mentions the 

 capture near Oldham, in Lancashire, of a male specimen 

 which had all the wings of a bright yellow colour. Have 

 there been any similar captures in this country ? If any 

 readers of the 'Entomologist' have made similar experinients 

 to mine, and been successful, 1 hope they will let us know 

 the results; also any information with respect to where this 



