70 BRITISH BUTTERFLIES. 



sulphureous preparation, called by druggists " milk of 

 sulphur." 



The only noticeable variation this butterfly is subject 

 to in this country is in the size of the orange wing- 

 spots, which are sometimes greatly enlarged. 



In a well-marked variety, common in the south of 

 Europe, Madeira, &c., this enlargement reaches a great 

 development, nearly the whole of the upper wings being 

 suffused with a deep orange, though in all other respects 

 the insect does not differ from our common form. This 

 beautiful variety has been described as a different species 

 under the name of Gonepteryx Cleopatra; but M. 

 Boisduval has proved that they are identical, by rearing 

 both the ordinary Rhamni and the Cleopatra from the 

 same batch of eggs. 



The female Cleopatra does not differ materially from 

 Rhamni. I look on this variety as very interesting, as 

 a probable instance of the direct effect of increased 

 warmth of climate in intensifying colour. 1 



Plentiful as this butterfly is in all the southern 

 counties, and extending in more or less abundance as 



1 Cleopatra, as Duponchel observes, is found in France, only in 

 the hottest parts, and is first seen as we go southwards, about 

 Avignon, but abounds most on the shores of the Mediterranean.- 



Why the two varieties Cleopatra and the common Rhamni 

 fly together we cannot fully explain ; but it is possible there 

 may be a constitutional difference between individual insects, 

 just as we see that of two Englishmen going to a hot climate, 

 one will brown deeply, while the complexion of the other 

 will hardly alter, though exposed to the very same external 

 influence. 



