407 ISLAND LIFE 



They thus afford examples of discontinuous specific 

 distribution exactly parallel to that of the great spotted 

 kingfisher, already referred to as found only in the 

 Himalayas and Japan. 



Comparison of the Faunas of Hainan, Formosa, and 

 Japan, — The island of Hainan on the extreme south of 

 China, and only separated from the mainland by a strait 

 fifteen miles wide, appears to have considerable similarity 

 to Formosa, inasmuch as it possesses seventeen peculiar 

 land-birds (out of 130 obtained by Mr. Swinhoe), two of 

 which are close allies of Formosan species, while two others 

 are identical. We also find four species whose nearest 

 allies are in the Himalayas. Our knowledge of this island 

 and of the adjacent coast of China is not yet sufficient to 

 enable us to form an accurate judgment of its relations, 

 but it seems probable that it was separated from the 

 continent at, approximately, the same epoch as Formosa 

 and Japan, and that the special features of each of these 

 islands are mainly due to their geographical position. 

 Formosa, being more completely isolated than either of the 

 others, possesses a larger proportion of peculiar species of 

 birds, while its tropical situation and lofty mountain ranges 

 have enabled it to preserve an unusual number of Hima- 

 layan and Malayan forms. Japan, almost equally isolated 

 towards the south, and having a much greater variety of 

 climate as well as a much larger area, possesses a somewhat 

 larger number of mammalia than Formosa, and an even 

 larger proportion of peculiar species. Its birds, however, 

 though more numerous are less peculiar ; and this is 

 probably due to the large number of species which migrate 

 northwards in summer, and find it easy to enter Japan 

 through the Kurile Isles or Saghalien.^ Japan too is 

 largely peopled by those northern types which have an 

 unusually wide range,and which, being almost all migratory, 

 are accustomed to cross over seas of moderate extent. 

 The regular or occasional influx of these species prevents 



^ Captain Blakiston has shown that the northern island — Yezo — is much 

 more temperate and less peculiar in its zoology tlian the central and 

 southern islands. This is no doubt dependent chiefly on the considerable 

 change of climate that occurs on passing the Tsu-garu strait. 



