1 5^ Jeffries on the Primaries of Birds. 
feathers more or less modified. Here it is only necessary to note 
that since all feathers are in quincunx order, they bear definite 
relations to each other. 
The feathers of the anterior edge run in two or more rows 
along the fore-arm and hand, certain ones being modified to form 
the spurious wing. Since these are continued to the very tip of 
the index finger they often fall into rank with the primaries and 
coverts of the opposite aspect, and hence can not be distinguished 
by their geometrical relations from the primaries and coverts. 
They can be distinguished from primaries, however small, by their 
relations to the finger bones. The primaries are always on the 
so-called flexor face, the feathers of the anterior surface are on the 
opposite face. As a rule these two surfaces are separated by 
the tip of the index finger, which, generally, projects, and in 
young Ducks bears a claw. 
There is no positive distinction between any of the feathers as 
regards structure and shape. The feathers of the upper and 
lower surfaces gradually shade into the primaries. Professor 
Baird has endeavored to distinguish the primaries from the coverts 
by their colors. But Dr. Coues has shown that the difference in 
color, when present, does not always separate the coverts from 
the primaries, and that in many species there is no difference in 
color. vSo we are forced to the conclusion that the only reliable 
means of determining a primary or other feather is by its position. 
i\llowing that position is the true key to the homology of the wing 
feathers, it is evident that in all attempts to determine the number 
of primaries in birds we should begin with the most simple con- 
dition of the feather ; in short, we should study the embryo and 
fledgeling. The study of these also has the advantage that they 
are much less specialized than the adult. 
I shall now take up several of the groups of birds represented 
in North America in relation to the number of their primaries, 
considering the young whenever they have been procurable. 
Oscines . In a young nine-primaried bird, as Melospiza melo- 
da , nine nearly equal conical papillae will be seen on the j:>osterior 
edge of the hand, and besides these a much smaller one on the 
extreme tip of the wing. These are the papillae of the nine de- 
veloped and the rudimentary primary. Immediately above these 
on the dorsal surface are nine small points projecting from the 
skin between the bases of the primaries ; these are the papillae of 
