ScHARFF — On the Origin of the Eurojyean Fauna. 485 



their ground in gradually decreasing numbers, discontinue to spread. 

 The older members of the southern migration are therefore in Ireland 

 more or less confined to the south-western counties. ISTot only are 

 they there in a climate more in accordance -nith their original habitat, 

 but what is of more importance, the struggle for existence is less 

 keen there, as comparatively few of the later immigrants from Southern 

 and Central Europe have penetrated to that part of Ireland. It must 

 be remembered that these changes went on very gradually step by 

 step. Though the number of the south-western species that migrated 

 north probably grew less as the more eastern forms increased, there 

 can be no doubt that some continued to advance north even after 

 Ireland was separated from England. 



We come now to the consideration of the Central European branch 

 of the southern migration. This includes, as we have seen, chiefly 

 species of South and Central European origin, but others of Asiatic 

 origin joined in it. Thus the badger {Meles taxus) belongs to the 

 last group. It is undoubtedly of Asiatic origin. Pour allied species, 

 ITeles leucurus, M. chinensis, If. ca?iesce)is, and M. analcuma, inhabit 

 Asia, whilst two, viz. If. ^^olali, and M. maraghaniis are known from 

 the Upper Miocene of Persia. That on entering Europe it has not 

 been able to make use of the ancient land-connexions above referred 

 to, is indicated by the fact of its absence from Sicily, Sardinia, and 

 Corsica, as well as from Northern Africa. On the other hand, Greece 

 was still united with Asia Minor at that time, for it is an inhabitant 

 of several of the islands in the Greek archipelago (27). 



As examples of the first group migbt be quoted a number of land 

 mollusca, such as Selix rufescens and S. ericetorum. Most of the 

 nearest relations of the former are confined to Central Europe, and it 

 does not range to the south-west. The allies of S. ericetorum have a 

 wider distribution, and some even penetrate into Western Asia. 



If, as I think, it may be taken as an established fact that the 

 south-western branch of the southern migration is the first, and the 

 Siberian migration the last, which reached tbe British Islands, Ire- 

 land must liave become disconnected from England during the period 

 intervening between the two. It was, therefore, at the time while 

 tlie migration from Southern and Central Euj-ope was in progress, that 

 the old land-connexion uniting the two countries was severed. That 

 migration, however, did not stop when the Siberian animals invaded 

 Europe. Again, we find the southern forms joining in with those of 

 totally different origin in their wanderings, just as the south-western 

 fauna and flora joined with the Central European. We still have, 



