36 BIRDS OF THE JAPANESE EMPIRE. 



only an accident that they have been recorded from Yezzo but not 

 from Hondo. Precisely the same remark applies to many of the 

 latter species ; they must have passed Yezzo, and they may have passed 

 the Kuriles in order to get to Hondo. There are, however, amongst 

 the resident birds, three remarkable instances of species inhabiting 

 Siberia and Yezzo which. are represented in Hondo by allied but 

 different species : — 



Gecinus canus is represented in Hondo by Gecinus awokera. 



Garrulus brandti is represented in Hondo by Garrulus japonicus. 



Acredula caudata is represented in Hondo by Aeredula trivirgata. 



A third point of view from which the birds recorded from the 

 Japanese Empire may be regarded, is in relation to those recorded 

 from the British Islands. About 130 species in each list are abso- 

 lutely identical, or so closely allied that they are not regarded as 

 more th an subspecifically distin-ct . An analysis of the species belonging 

 to each suborder, and, in the case of the Passeres, of those belonging 

 to each family, represented in the two districts, shows a remarkable 

 similarity between the two faunas, which is all the more remarkable 

 when the relative position of the two groups of islands to the 

 mainland is taken into consideration. 



The Japanese Empire consists of a range of islands extending from 

 Kamtschatka, in latitude 53-|°, southwards to Formosa, in latitude 

 23^°, a range of thirty degrees. A similar range on the Atlantic 

 coast of the Palsearctic Region would extend from Yorkshire to the 

 Canary Islands. The parallels of latitude have, however, little to do 

 with the distribution of birds^ which appears to be governed by the 

 Isothermal Lines. The January isothermals of the Japanese Empire 

 transferred to the European coast would range from Cherry Island 

 to Gibraltar ; those of July from John o' Groat^s to the 'Cape Verd«s ; 

 whilst those of mean annual temperature would range from Iceland 

 to the Canaries. Japan proper, from the north of Yezzo to the sonth 

 of Kiu-siu, is much less extensive, and only ranges from 44|° to §1°, 

 or only thirteen degrees and a half. A similar range on the map of 

 Europe would extend from Bordeaux to Morocco. The corresponding 

 January isothermals would range from Jan Mayen to Lisbon, those 

 of July from London to the Canaries, whilst those of mean annual 

 temperature would raaige from the Orkneys to Gibraltar. 



With a climatic range of so much greater extent than is possessed 

 by the British Islands, it would be reasonable to expect that the 

 number of species found in the Japanese Empire should much exceed 

 those of its Atlantic rival, were it not for other considerations. 



The ornithology of the British Islands has been studied for a 



