C. J. Sundevall on the Wincjs of Birds. 413 



large enough nearly to displace the largest covert-feathers, 

 which lie as if firmly grown to the tubes of the quill-feathers. 

 The same thing is met with, more or less, in all birds which 

 have broad wings, and consequently large arm-feathers j but 

 if we compare the Song-birds with other birds which have 

 these feathers equally large *, we shall always find that 

 the former have the feathers resting with a larger part, in 

 proportion to their size, upon the ulna, and consequently 

 also more firmly attached to it, and the covert-feathers 

 more strongly attached to the quills. In the Water-birds, 

 and in general in those which have short quill-feathers, the 

 latter are placed almost behind the wing-bone, and so loosely 

 attached as to possess considerable mobility, and the covert- 

 feathers are inserted separately from the quill-feathers as a 

 distinct series, because the quills are thin and leave consider- 

 able interspaces. In this, as in so many other points, Picus 

 approaches the Song-birds. 



B. The smaller Feathers of the Upper Surface of the Wing. 



These feathers are always most developed on the cubitus, 

 where they are also most easily seen and examined ; there- 

 fore we will start from that part. They have usually all been 

 designated by the common name of coverts. They are of 

 the following kinds : — 



1. Tectrices majores (great wing-coverts, Pteromata, IlLf, 

 figs. 3, 7, k, I) form a single series which is always situated 

 immediately within upon the roots of the quill-feathers. 

 They always retain much resemblance in form, texture, and 

 colour to their corresponding quill-feathers, and are always, 

 like the latter, destitute of accessory plumules. They 



* E. g. Corvus, Turdus, Hinmdo, and Cinches, compared with Strix or 

 Aquila, LaruSj Fcdco, and Anas. 



t The cause of my not setting this name in the first place is that it has 

 never been generally accepted, and that we must not increase the number 

 of terms except when it is clearly unavoidable or decidedly advantageous. 

 The Swedish name " flygpenntacken," adopted by Marklin in the trans- 

 lation of Illiger's ' Termiuologie,' may be admissible as containing its own 

 explanation. 



