568 BIBLIOGRAPHICAL APPENDIX [2 



least note on the subject ; and with them are also given, as 

 separate titles, the reviews and notices which appertain. As 

 already hiated, I give the benefit of the doubt to a few titles 

 whose claim to a place here is doubtful, or which are of such 

 mixed character that arbitrary decision is required ; for it is 

 well understood that a perfect classification of titles by sub- 

 ject-matter is a bibliographical impossibility. 



For present purposes, "North America " is held to include 

 Greenland, Mexico, and the Bahamas and Bermudas; but 

 neither the West Indies nor America south of Mexico. 



The titles herewith presented, nearly or about one thousand 

 in number, are simply those which I have thus far compiled for 

 my Universal Bibliography of Ornithology; but they are sup- 

 posed to be about 95 per cent, of all that are extant on this 

 particular subject, and to represent some three or four per 

 cent, of the whole literature of ornithology. The whole num- 

 ber of titles I have in hand at present writing is believed to be 

 about 18,000. The present set of titles is arranged chronolo- 

 gically, with secondary alphabetization under each date. This 

 method, I am persuaded, tends to the best exhibit of the sub- 

 ject in its natural connections and bearings, because the move- 

 ment of the bibliography corresponds with the progress of the 

 science ; and any objections to such an arrangement are re- 

 moved by the two indexes, of authors and of localities, by 

 which any desired title may be found at once. 



There is little to be said of the way in which the work has 

 been done ; for if it cannot speak for itself, the less said the 

 better. It should be stated, however, that the compiler has 

 habitually regarded The Title as a thing no more to be 

 mutilated than a man's name ; and that he has taken the 

 utmost pains to secure transcription of titles verbatim, lite- 

 ratim €t punctiiatim. It may be added, that, excepting in 

 certain specified cases, no title in this BibUography has been 

 taJcen at second-hand. 



The remarks which follow most of the titles have been made 

 at the compiler's discretion, and are of the most miscellaneous 

 description. In general, however, they are in amplification 

 or explanation of the title, rather than in the way of criticisui. 

 They are in general brief, and more so than might be expected 

 in a case like the present; but it will be remembered that they 

 form part of a commentary on many thousand titles, no one 

 set of which is given preference — such extensive commentary 

 demanding of course the utmost condensation. 



