656 
BIRDS. 
Fic, 360.—Types of feathers. 
feather in sheath (s%.). 
eon—C., calamus ; 
(4.$.). 
ortion 
Sy 
3, Covert of heron showing aftershaft 
ftershaft; F., rachis; V., vane. 
bilicus (S.%.), pith (P.); #., filoplume. 
4S. 
bilicus (7.2. ), superior um 
al 
ing f 
pig! 
feather oF 
ferior um 
2, Develop 
, Secondary, 
quill showing in! 
Down. 
4 
of 
Ds 
