192 Mr. A. Newton on the Possibility 



parallelism which obtains in certain families or genera inhabiting 

 the Greater Antilles has been noticed, and a comparison made 

 between the number of New-World and European species which 

 find their way as stragglers to our shores. But little has been 

 ascertained with respect to the distribution of British birds. 

 However, I know that one of my friends, distinguished by his 

 remarkable diligence, has now for some time been employed 

 on this deeply interesting subject, and as I trust that before 

 long he will have made sufficient progress to offer to the public, 

 in these pages, some of his investigations, I will say no more on 

 this head, but turn to what I conceive will prove to be the most 

 important result of such an inquiry as I have indicated. 



Two of the expressions which have lately become very familiar 

 to the ears of naturalists are the " Struggle for Life," and the 

 " Preservation of Favoured Races " therein. Each of these 

 points, as it seems to me, would be greatly elucidated by the 

 carrying-out of Mr. Wolley's idea. Every one must admit our 

 present knowledge respecting them to be very meagre, and 

 I cannot help thinking that before we can assign any cause for 

 the predominance of one species over another, we should strive 

 to ascertain the measure of that predominance. I confess I 

 hardly know yet, which is to be regarded as the dominant species 

 of bird in a small and well-explored country like England, I 

 believe there are many more naturalists who will confess the 

 same. The different local lists that have been published scarcely 

 enable us to form an opinion on the subject, excellent though for 

 other purposes they may be. Seldom do we find in them more 

 definite intelligence concerning a given species than that it is 

 "common" or "rare" — expressions which often refer as much 

 to the individual powers of and opportunities for observation 

 possessed by the compiler, as to the peculiarity of the species ; 

 and expressions which must always be vague, if not arbitrary. 

 Still more difficult is it to say why in one part of England a 

 species is abundant or scarce, compared with what it is in another. 

 Of course there are some exceptions to this, which will imme- 

 diately occur to the reader^s mind, as in the case of sea-birds 

 not frequenting the interior, or mountain -birds not inhabiting 

 the level country. But can any one say why, in Devonshire, the 



