415 
C. J. Sundevall on the Wings of Birds. 
This is due not only to the greater length of the remiges 
in the Song-birds, but really also to the greater length of 
the coverts in proportion to the body in the other orders, 
which distinctly shows that in the Raptorial birds, Ardece , 
Ciconiae , and all other birds of which the cubital remiges are 
comparatively of the same length as those of the Song¬ 
birds, the coverts reach beyond their middle. Cinclus , 
which has shorter cubital remiges than other Song-birds, 
nevertheless retains the proportions of that order, and a direct 
comparison between nearly equally large, and in other respects 
similar, species shows it distinctly, e. g. Hirundo , Turdus , 
Corvus, compared with Cypselus, Cuculus, Coracias (see fig. 10, 
Turdus , fig. 11, Cuculus). In some Water-birds and small 
Waders the great cubital coverts are but little shorter than 
the remiges; in other respects they present many peculiarities, 
e.g. in Gallus ! 
If this difference in the size of the coverts be taken to¬ 
gether with the difference which will be mentioned below 
(under § 3), it is the most easily recognizable and most 
general of all the external characters at present known by 
which the Song-birds are differentiated from the other orders. 
2. Tectrices secundce seriei (the coverts of the second 
row, m, n), which lie immediately upon the greater coverts, 
generally resemble the ordinary feathers of the body. Those 
which belong to the cubitus have usually the peculiarity 
of lying reversed with relation to the greater coverts and 
the remiges, so that the inner margin of each feather 
(that turned towards the humerus) is free and covers the 
outer margin of the next one. But I have always found 
them unreversed in Trochilus , Coracias , Cuculus , Columba , 
Gallus , Lestris , Lotus, Sterna , and Uria, as well as in young 
Song-birds in their first dress*. They are inserted in 
the skin either immediately behind the muscular layer, 
* Mr. W. v. Wright has kindly communicated to me the observation 
made by him, that some of those which lie far back on the cubitus, 
together with the corresponding feathers of the next series (§ 3), resume 
the right position (like the remiges) in all Gallinse and Water-birds (see 
fg- 3, n, n ). 
