has been done once for all, as far as existing literature is concerned. 

 (2) A full description of the external characters of both sexes, and, 

 as far as possible, all stages of plumage. (3) A general account of 

 the habitat of the species. (4) A list of every individual specimen 

 in the Museum collection, with a statement as to the source from 

 whence it was obtained and its original locality. Besides numerous 

 woodcut illustrations interspersed in the text in many of the 

 volumes, intended to show the principal structural modifications 

 by which the minor groups are distinguished, the work contains 

 altogether three hundred and eighty-seven coloured plates of species 

 which had never been previously figured, or at aU events not in an 

 adequate manner. The specimens from which these drawings were 

 made are in almost every case the types of the species, and altogether 

 five hundred and forty have been figured. 



The vast increase of material for the study of the subject which 

 has accrued since the commencement of the work may be estimated 

 by the fact that the number of specimens in the Museum has, 

 through the munificent donations of several large collections, notably 

 those of Messrs. F. D. Godman and 0. Salvin, A. 0. Hume, R. G. 

 Wardlaw-Ramsay, and H. Seebohm, and the acquisition by purchase 

 of others, scarcely less important, increased from about 35,000 in 

 1872 to nearly 400,000 at the present time. It must be noted, 

 moreover, that this increase has taken place notwithstanding the 

 continual weeding-out of all absolute duplicates. The earlier 

 volumes therefore represent a very inadequate idea, both of the 

 present condition of knowledge of the subject and of the contents 

 of the Museum collection. To remedy this defect it is proposed to 

 issue a Supplement (probably in two volumes) which wiU contain 

 references to every species described subsequently to the publication 

 of the volume which treats of the group to which it belongs, and 

 also such emendations as the progress of Zoology seems to require. 

 When this is published, it will afford a complete list up to date of 

 all known birds, either described in the Catalogue or elsewhere. 



