254 HISTORY OF THE EUROPEAN FAUNA. 



a few species likewise found their way into Europe. 

 Many other mammals have wandered still farther 

 west, and now form an important percentage of the 

 European fauna. 



Of Birds, too, a large number might be mentioned 

 which had their home in Asia and have found their 

 way to Europe with the Oriental migrants. A few 

 instances have already been alluded to, and somq 

 additional ones may be specified at random, without 

 attempting to give a complete list. 



Some of the Wagtails (Motacilla), as I men- 

 tioned in the last chapter, have certainly come to 

 us with the Siberian migration; but others seem 

 to be Oriental, such as Motacilla melanope, which is 

 resident in Southern Europe and migratory in the 

 North. M. campestris the Yellow Wagtail has 

 a most peculiar discontinuous range. One colony 

 breeds in the British Isles and Western Europe 

 generally, where it is known as a summer visitor, 

 retiring to W T est Africa during winter; another is 

 found from South-east Russia to Turkestan in 

 summer, and winters in Southern Africa. This fact 

 may possibly be due to two distinct migrations from 

 Asia having taken place: an earlier one from the 

 South-east that is to say, an Oriental one and 

 a Siberian one more recently. In this case the 

 members of the two migrations have not become 

 sufficiently differentiated to be regarded as distinct 

 varieties. Though most of the Wagtails have a 

 somewhat northern range, none (except perhaps M. 



