402 C. J. Sundevall on the Wings of Birds. 
In the Song-birds, without exception, the first feather is 
abbreviated. In a somewhat higher degree this takes place 
in two different ways. In a part of them some of the 
feathers (the anterior) are gradually shortened, by which 
means the wing becomes short and rounded, and the first 
feather somewhat shorter than the second (e. g. Garrulus , 
Regulus , Timalice, Myiothera) ; these birds usually fly badly, 
are seen much upon the ground, and do not fly far. In 
others the feathers of the first finger-joints (nos. 2-4) are 
moderately long and exceed the others; but when this 
occurs among the Song-birds it is usual for the first feather to 
be so reduced in size that it either remains as a small rudi¬ 
ment or entirely disappears; and in this latter case there are 
only nine primaries (as in fig. 8). This reduction of the 
first feather is peculiar to the Song-birds, but among them 
it is quite usual. We may, indeed, estimate that one fourth 
of the known species are destitute of the first quill-feather, 
one fourth have it rudimentary, one fourth have short 
rounded wings with ten primaries, and the remaining fourth 
have tolerably long wings, but with the first feather shorter 
than those that follow (e. g. Corvus, exotic Muscicapas , 
&c.). It would appear therefore as if in the Song-birds there 
was a compensation between the development of the feathers 
of the first and second joints of the finger, so that the increase 
of the latter brought with it a diminution of the first feather. 
The first feather is deficient especially in many American 
species; namely, the American Sylvias and their allies, in the 
Tanagras , Euphone , Hirundo , and all American Sturninse and 
Passeres. In the Old Continent it is deficient in Anthus, 
Motacilla, Hirundo , and in about one half of the Passeres. 
A rudimentary first wing-feather occurs in America almost 
solely in the Turdi; but in the Old World in the Turdi and 
Sylvias and many of their allies, in the Lanii (pars), Gracu- 
linse, Cinnyrinae, Alaudse, and the Ploceini among the 
Passeres. 
The decrease in size of the outer quill-feathers, or their 
disappearance, is generally shown more in the fully de¬ 
veloped dress and in the males than in the winter garb or 
