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 1860; 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 
f new departure 3 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 subject 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 
f 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 
