382 Recently published Ornithological Works. 



same areas. This led to the discovery of laws of geographi- 

 cal variation, connecting particular phases of local differenti- 

 ation with the topographical and climatic peculiarities of the 

 regions where they so uniformly occur. Many of the isolated 

 facts bearing on this subject had been observed and placed on 

 record prior even to 1880; but their full import was not rea- 

 lized till after the lapse of another decade, during which our 

 stores of material had become vastly increased. In 1871 the 

 ' new departure ' was for the first time fairly entered upon, 

 which in three years revolutionized the nomenclature of 

 North- American ornithology, adding an important chapter 

 on philosophical zoology, and exerting great influence in 

 many other departments of North-American zoology. Natu- 

 rally a view that threatened either to assign fully one sixth 

 of the previously recognized species to the limbo of syno- 

 nymy, or to lower them to the grade of geographical races, 

 was not rashly espoused by those to whom belonged the 

 credit of the recognition and description of these previously 

 supposed specific forms ; but so overwhelming were the facts 

 in its favour found to be, that one after another of our leading 

 writers soon gave it their endorsement, so that probably a 

 greater degree of unanimity of opinion respecting any pro- 

 blem in ornithology never obtained than now exists among 

 our ornithologists respecting the sul)jcct of geographical vari- 

 ation among our birds, and the subspecific relationship of 

 many forms which, when first made known, seemed unques- 

 tionably of specific rank. 



"■ The next step, and apparently a wholly logical one in the 

 revolution, will doubtless be the general adoption of a trino- 

 mial system of nomenclature for the more convenient expres- 

 sion of the relationship of what are conventionally termed 

 ' subspecific,^ so that we may write, for instance, Falco com- 

 munis anatum in place of the more cumbersome Falco com- 

 munis, subsp. anatum. This system is already, in fact, to 

 some extent in use here, though looked upon with strong dis- 

 favour by our transatlantic fellow-workers, who seem as yet 

 not fully to understand the nature of the recent rapid ad- 

 vance ornithology has made in this country^ or to appreciate 



