lo LEPIDOPTERA. 



other convenient projection, where, its fore wings hanging back 

 witl^ the front margin of the hind wings thrust forward, it 

 has much the appearance of a pair of withered poplar leaves. 



It ajDpears to occur in all parts of the United Kingdom 

 except in the extreme north of Scotland, but is scarce in the 

 extreme west of England and of Wales. In Ireland it seems 

 to be more frequent, occurring wherever poplar is common. 

 Formerly it was very abundant in the south of England, and 

 even in London, occurring commonly in the squares and 

 gardens ; in the Surrey Zoological Gardens, for instance, 

 when they existed, it was plentiful. Now however it is 

 rarely seen in the suburbs of London, and seems to be 

 generally less common throughout the country. 



Abroad it is abundant throughout the greater part of 

 Europe and large portions of Asia. 



This species and the preceding, being of about the same 

 size and emerging from the pupa at the same period, have 

 long been recognised as suitable subjects for experiments in 

 hybridization. These experiments have to some extent been 

 successful, the offspring of such ill-assorted pairs having 

 repeatedly been reared, though with difficulty, from the 

 delicacy of constitution of the larvas. Such specimens 

 however have not proved to be capable of reproduction, and 

 indeed are said to be, very often, gynandrous. In markings 

 and colour they vary greatly, but are usually inferior in 

 brightness of colour and distinctness of markings to both 

 parent species ; the antennas are usually smaller than those 

 of either parent, and in those which show male characters 

 the pectinations are shorter. In the majority, if not in all 

 the successful cases, the male parent seems to have been 

 ocellatus, the female 2'f'P'^^^'^- The earliest recorded case of 

 rearing such hybrids which I can find, took place in 1857, 

 when twelve specimens of one brood were reared, all of which 

 are stated to have been much alike, almost exactly inter- 

 mediate in appearance between the species, as well as inter- 

 mediate in sex. Another batch was much more variable : 



