ClipArt ETC
"From the head, backward to the tail, the body feathers increase in strength and size, also alter in form; those on the face, or around the base of the bill, being the smallest, the tail coverts longest."

Neck-Covert

"From the head, backward to the tail, the body feathers increase in strength and size, also alter in…

"From the head, backward to the tail, the body feathers increase in strength and size, also alter in form; those on the face, or around the base of the bill, being the smallest, the tail coverts longest."

Tail-Covert

"From the head, backward to the tail, the body feathers increase in strength and size, also alter in…

"Details of Engyptila albifrons (White-fronted Dove); head and foot natural size; wing and tail reduced.

White-fronted Dove Details

"Details of Engyptila albifrons (White-fronted Dove); head and foot natural size; wing and tail reduced.

"The more angular the wing of birds - that is to say, the longer the feathers on the edge of the wing - the more rapidly does it propel itself through the air."

Wing of an Eagle

"The more angular the wing of birds - that is to say, the longer the feathers on the edge of the wing…

"The feathers are horny productions, consisting of a hollow tube or barrel and a stem rising from it."

Feather Shaft

"The feathers are horny productions, consisting of a hollow tube or barrel and a stem rising from it."

"The feathers are horny productions, consisting of a hollow tube or barrel and a stem rising from it."

Feather Tube

"The feathers are horny productions, consisting of a hollow tube or barrel and a stem rising from it."

"The feathers are horny productions, consisting of a hollow tube or barrel and a stem rising from it. The webs are convex above, and are thus enabled to resist flexion or fracture from beneath better than from any other direction."

Feather Web

"The feathers are horny productions, consisting of a hollow tube or barrel and a stem rising from it.…

"The feathers are horny productions, consisting of a hollow tube or barrel and a stem rising from it."

Wing of Kamichi, or Crested Screamer

"The feathers are horny productions, consisting of a hollow tube or barrel and a stem rising from it."

"Besides flight, birds possess other means of locomotion, being formed for walking, swimming or flying, according as their habits are aerial, terrestrial or aquatic."

Wing of a Penguin

"Besides flight, birds possess other means of locomotion, being formed for walking, swimming or flying,…

"In the feathers of a large portion of birds there is a plumiform formation."

Plume

"In the feathers of a large portion of birds there is a plumiform formation."

"This plumule is conspicuous in gallinaceous birds."

Plumule

"This plumule is conspicuous in gallinaceous birds."

"Hirundo horreorum. Barn Swallow. Tail deeply fornicate, nearly or about as long as the wings; lateral feather linear-attenuat, about twice as long as the middle feather." Elliot Coues, 1884

Barn Swallow Tail

"Hirundo horreorum. Barn Swallow. Tail deeply fornicate, nearly or about as long as the wings; lateral…