1876.) Progress of Ornithology in the United States. 549 
_ analytically, and forms from distant, little-known localities which 
differed slightly from their near affines of neighboring regions 
were looked upon as distinct “ species.” Later, as the material 
for a better knowledge of the subject accumulated, specimens of 
an intermediate character came to light, which, so long as they 
were few, were naturally looked upon as probably hybrids be- 
tween the forms whose characters they seemed to combine. 
Still later, however, it was found that certain strains of deviation 
from pronounced types occurred in a large number of species 
belonging to widely different families inhabiting the same areas. 
This led to the discovery of laws of geographical variation, con- 
necting particular phases of local differentiation with the topo- 
graphical 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 realized 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 revolution- 
wed the nomenclature of North American ornithology, adding an 
important chapter to philosophical zodlogy, and exerting great 
Influence in many other departments of North American zodlogy. 
Naturally, a view that threatened either to assign fully one sixth 
of the previously recognized species to the limbos of synonomy 
r 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 speci- 
fic forms; but so overwhelming were the facts in its favor found 
lobe, that one after another of our leading writers soon gave it 
ng indorsement, so that probably a greater degree of unanim- 
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of opinion respecting any problems in ornithology never 
. obtained, than now exists among our ornithologists respecting 
the subject of geographical variation among our birds and the 
sub-specific relationship of many forms which when first made 
. own seemed unquestionably of specific rank. ; 
The next step, and apparently a wholly logical one in the 
tevolution, will doubtless be the general adoption of a trinomial 
; m of nomenclature for the more convenient expression of 
as relationship of what are conventionally termed “ sub-species,” 
D that we may write, for instance, Falco communis anatum in 
Place of the more cumbersome Falco communis subsp. anatum. 
‘ystem is already, in fact, to some extent in use here, 
Cie a a ABD oa 2 epi ON NEN REE 
