366 



GENERAL ZOOLOGY 



of a fully developed feather we may choose one of the con- 

 tour-feathers (Fig. 190, A) which form the main body-covering. 

 It consists of a hollow base, the quill (Fig. 190, A, l), from 

 which arises an expanded portion called the vane. Through 

 the center of the vane runs the rachis (Fig. 190, A, 2), which 

 gives off branches called barbs. From the barbs run inter- 

 locking structures 

 (barbules), bearing 

 hooks which serve 

 to bind the vane 

 into one continu- 

 ous surface. At 

 the junction of 

 quill and rachis on 

 the under surface 

 of the feather a 

 tuft of down, the 

 after shaft (Fig. 

 190, A, 3), is often 

 found. The wings 

 and tail bear 

 feathers which are 

 contour-feathers 

 of large size and 



with very firm 

 FIG. 190. Kinds of Feathers of Pigeon J , 



vanes. Scattered 



A, contour-feather: 1, quill ; 2, rachis; 3, aftershaft. aTnonp , thp pfm 

 fl.filoplume; C, down-feather * among 



tour-feathers are 



down-feathers (Fig. 190, C f ), with which the nestling pigeon 

 was covered, and hair-like feathers, orfiloplumes (Fig. 190, B). 

 Down-feathers differ from contour-feathers in having no 

 barbules, so that the barbs are not held together, but 

 make a fluffy mass. Filoplumes bfrye only a main axis with 

 few barbs. 



