ClipArt ETC
"Types of feathers. D., Down. 2, Developing feather in sheath (sh.). 3, Covert of heron showing aftershaft (A.S.). 4, Secondary feather of pigeon--C., calamus; A.S., aftershaft; R., rachis; V., vane. 5, Portion of quill showing inferior umbilicus (I.u.), superior umbilicus (S.u.), pith (P.); F., filoplume." -Thomson, 1916

Feather Types

"Types of feathers. D., Down. 2, Developing feather in sheath (sh.). 3, Covert of heron showing aftershaft…