THE ORIENTAL MIGRATION. 265 



few localities in the east of England. The members 

 of the family Papilionidce, to which it belongs, are 

 mostly large and striking species, and their distri- 

 bution is therefore more accurately known than 

 that of the smaller and less conspicuous butterflies. 

 Only four different kinds of Swallow-tail Butterflies 

 inhabit Europe, but in Southern Asia and the Malay 

 peninsula they attain their maximum as regards 

 numbers; and there we find a great many species of 

 this genus Papilio. Of the four European species only 

 one, viz., Papilio hospiton, is peculiar to Europe ; all 

 the others range into Asia. It would seem, therefore, 

 as if this genus was an Asiatic one and had migrated 

 to Europe, and that the route taken was the one from 

 Asia Minor across to Greece. We have a similar 

 case in the closely allied genus Tliais two of the 

 three European species living also in Asia Minor. 

 Thais cerisyi inhabits some of the Greek islands, as 

 well as the mainland of Turkey and Greece. 



Another genus of the great family Papilionidce 

 with which most lepidopterists are well acquainted 

 is Parnassius. What butterfly- hunter has been in 

 Switzerland without hearing of, or seeing, the famous 

 Parnassius Apollo ? We have four European species of 

 Parnassius t only one of which is peculiar to our con- 

 tinent, but the locality where it occurs, the Caucasus, 

 is on the borders of Asia. Almost all the other 

 species are Asiatic, none however range to the south. 

 Its headquarters, and I think its original home, are 

 the mountains of Central Asia. From there it 



