iv PREFACE 



Himalayan Range above about 6,000 feet, stretching to the 

 south of Tibet, and north of the valley of Yang-tse-kiang as 

 far as the Pacific, and then round Corea and the main islands of 

 Japan, with of course all the countries lying to the northward 

 of a line so indicated, but it seems to be admitted that these 

 limits cannot at present be more definitely drawn. 



This work being primarily intended for the use of field- 

 naturalists and travellers, I have thought it advisable to cut 

 as short as possible all technical questions, such as synonymy 

 and the like. The arrangement followed is very nearly the 

 same as adopted in the Birds of Europe, with of course the 

 additions rendered necessary by the larger ground that has to 

 be covered. It will be seen, however, that the extreme sub- 

 division of genera, species, and subspecies now so much in 

 fashion has been avoided, and this, I think, will be found a 

 practical convenience to the field-worker. The endless manu- 

 facture of subspecies in particular, often based on very trifling 

 differences of tint, seems calculated rather to puzzle and dis- 

 courage than to assist the beginner, for even the expert is apt 

 to find himself lost in investigating slight distinctions which 

 are occasionally not much more than those which separate 

 individuals. No one can doubt that in most cases the wider 

 the area over which a species ranges, the greater is the amount 

 of variation to be found among its members, the variation 

 being apparently due to climatic or other local causes. When 

 fairly defined limits can be assigned to such variations, it is 

 quite legitimate to accord them separate treatment, whether 

 they be called subspecies or not ; but when every intermediate 

 stage between examples that are most unlike can be found, the 

 attempt to differentiate them more than Nature herself has 

 done seems entirely inexpedient. For this reason, besides 

 being in principle a binomialist, I have declined the recognition 

 of such so-called "subspecies," as those who have described 

 them have so little confidence in as to need the aid of 

 trinomials. 



The descriptions of the various species have been mainly 

 taken from specimens which were then in my own collection, 



