FLAP, _n._ See LOMA.
FLEX´ION, _n._ Bending (of a limb). Opposed to _extension_.
FLEX´OR, _n._ Generic name of a muscle that bends a limb or any of its
segments.
FLEXU´RA (_alæ_), _n._ Bend of the wing; carpal angle; salient angle or
prominence formed at the wrist when the wing is folded. (77.)
FLEX´URE, _n._ See FLEXURA.
FLOC´CULENT, _a._ Pertaining to the peculiar down of newly hatched or
unfledged young birds. (Not used in ornithology in its common sense of
_flaky_.)
FLOC´CUS, _n._ A peculiar kind of plumage of simple structure (generally
downy), found in unfledged birds, at first growing directly from the
skin, afterwards for the most part affixed to the tip of the true
feather, of which it is the precursor, or rather the first-formed
part; and finally falling off. In psilopædic birds the floccus is only
associated with the true plumage, sprouting from the future pterylæ
alone; in ptilopædic birds it also sprouts from the apteria, and in so
far is unconnected with future plumage; the whole body is in such cases
densely clothed. (_Sundevall._)
FΫTUS, _n._ Same as FETUS (which see).
FOL´LICLE, _n._ Minute secretory sac.
FOLLIC´ULAR, FOLLIC´ULATE, _a._ Having follicles; composed of follicles.
FOOT, _n._ (112.) See PES.
FOOT-JOINT, _n._ Junction of toes collectively with the metatarsus.
(100.) See PODARTHRUM.
FORA´MEN, _n._; pl. _foram´ina_. Hole; opening; perforation. _Foramen
magnum_, the large hole in the occipital bone transmitting the neural
axis. _Foramen lacerum_, irregular vacuity between certain bones at base
of skull. The _foramen rotundum_ transmits the optic nerve; _foramen
ovale_, the trigeminal nerve; the latter is also a name of the opening
between right and left sides of the heart.
FORE´HEAD, _n._ Front of head from bill to crown. (34.) See FRONS.
FORE-NECK, _a._ Whole front of collum, from chin to breast; whole
throat. (51.) See GUTTUR.
FOR´FICATE, _a._ Deeply forked.
FORKED (_tail_), _a._ Having the outer feathers longest, the rest
gradually successively shortened to the middle pair; when these are
again lengthened somewhat, the tail is said to be _doubly forked_.
FOS´SA, _n._; pl. _fossæ_. Ditch; excavated place. Used chiefly in the
plural to denote the pits or grooves in which most birds’ nostrils open.
FOS´SIL, _a._ or _n._ Dug out of the ground. Particularly, any organized
body, or remains, trace, or mould of such body, naturally buried in past
time by geologic agencies. The _Archæopteryx macrurus_, of the Jurassic
formation of Solenhofen, a mesozoic bird, is the oldest known ornithic
_fossil_.
FOSSO´RIAL, _a._ Digging into the earth for a habitation.
FOS´TER. This word and its various compounds are used in their common
senses in treating of the relations of young cowbirds and young cuckoos
with the birds upon which they are parasitic.
FO´VEA, _n._ A slight depression.
FREE, _a._ Said of the leg when not enclosed to the knee in the common
integument of the body.
FRE´NUM, _a._ Bridle; hence, any cheek-stripe.
FRINGE, _n._ Marginal membrane; also, marginal row of feathers. (135.)
See LOMA.