366 



SAUKOPSIDA (BIRDS). 



feathers are in the wing attached to the bones of the hand . 

 these are known as "primary feathers" (fig. 207, A 1-10). 

 Yinother series arise from the ulna, the seromJnrij feathers {B). 



V 



c 



Fig. 20(5.— Fkather of Bird. 

 C, calamus ; R, rachis ; >', vexillum ; B, barbs. 



There is a small thumb in the bones of the wing ; this is 

 also provided with feathers, and is called the "bastard wing" 

 {BW). The bases of these large wing-feathers are covered by 

 smaller feathers, the " wing-coverts." The tail-feathers vary in 



