vi THE BRITISH BIRD BOOK 



within our shores, or which visit us at such rare and irregular intervals that they 

 can only be called British by courtesy. Notes on their distribution are added. 

 Their habits are not described, for as British birds they can scarcely be said to 

 have any worth recording. 



The second chapter, which must be taken in close connection with the de- 

 scriptions of the species in Section 1 of the Preliminary Classified Notes, shows to 

 what extent the Family and Generic structural characters can be used as a means 

 of identification. It has been found convenient to place under the same head the 

 periods and methods of the moults. 



The third chapter gives an account of the general migratory movements to and 

 from our shores, thus enabling the reader to see, in relation to the whole of which 

 they are parts, the migrations of the separate species described in Section 3 of the 

 Classified Notes. 



The fourth chapter contains information concerning bird-watching and photo- 

 graphy. A bibliography and an exhaustive index complete the work. 



The Classification of the Orders and Families adopted in the book follows that 

 of the Cambridge Natural History, except in respect to the arrangement of the 

 Families within the Order Passeres, which is new, and based upon the researches 

 of Mr. W. P. Pycraft. 



SOURCES OF INFORMATION 



Bibliographies consulted. The value of a work like the present depends 

 on there being at the disposal of the writers a body of evidence large enough to enable 

 them to verify the accuracy of any statement open to question. A systematic 

 effort has therefore been made to reach all the sources of information available ; 

 firstly, by consulting the published bibliographies, such as the Zoological Record 

 (1864- ), of which all the volumes have been examined, the Bibliotheca Zoologica, 

 1700-1880, Giebel, Thesaurus Ornithologiae, 1872-7, the Subject-Index at the British 

 Museum, the Catalogue of the Zoological Society, the Atlante Ornithologico of 

 Arrigoni degli Oddi, the list of Faunal publications in the Proceedings of the U.S. 

 National Museum, ii. 359-482, and similar lists by Mr. Miller Christie in the 

 Zoologist, 1890 ; secondly, by an inspection of the trade catalogues of the chief 

 European and American booksellers, and lastly by seeking the information from 

 leading ornithologists. Among those to whom special thanks are due for such help 

 are Dr. Carl Hennicke, editor of the Ornithologische Monatsschrift ; Dr. A. Reiche- 

 now of the Konigl. Zoologisches Museum, Berlin ; M. Louis Denise, editor of the 

 Revue francaise d' Ornithologie ; Ritter von Tschusi zu Schmidhoffen, editor of the 

 Ornithologisches Jahrbuch ; Dr. Hellmayr, Count Arrigoni degli Oddi, Mr. H. F. 



