V.

VACU´ITY, _n._ Deficiency in a part; as, a _vacuity_ in the bony palate.

VAGI´NA, _n._ Any sheath, in general. Particularly, the female sexual passage. In birds the lowermost tract of the oviduct is sometimes loosely so called.

VANE, _n._ (151.) See VEXILLUM.

VARIETY, _n._ A nascent species. Practically, the term designates a set of objects incompletely distinguished from others of the same species, by reason of slightness of the difference, or presence of connecting links.

VAS´CULAR, _a._ Permeated with blood vessels. Also equivalent to _circulatory_; as, the _vascular_ system.

VAS DEF´ERENS, _n._ Tube conveying semen from testes to cloaca.

VAS´TUS, _a._ for _n._ A certain muscle of the thigh.

VEIN, _n._ Vessel conveying blood from the capillaries to the heart. _Artery_ carries blood from the heart.

VE´NÆ CA´VÆ, _n. pl._ Large veins pouring blood from the system into the heart.

VE´NOUS, _a._ Pertaining to a vein; as, _venous_ blood, the _venous_ system.

VEN´TER, _n._ Lower belly. (Not well distinguished from _abdomen_, and little used.) (65.)

VEN´TRAD, _a._ Towards the belly.

VEN´TRAL, _a._ Pertaining to the belly.

VEN´TRICLE, _n._ Chamber of the heart, right or left, whence issue the pulmonary arteries and the aorta. Compare AURICLE. Also, a cavity of the cerebrum.

VEN´TRICOUS, _a._ Swollen; bulbous.

VENTRIC´ULUS BULBO´SUS, _n._ Same as _gigerium_.

VENTRIC´ULUS SUCCENTURIA´TUS, _n._ Same as _proventriculus_.

VERMICULA´TION, _n._ Very fine crosswise marking.

VER´MIFORM, _a._ Shaped like a worm; as, a woodpecker’s tongue. LUMBRICIFORM is the same.

VER´NAL, _a._ Relating to the spring.

VERRU´COUS, _a._ Warty.

VER´SATILE, _n._ Reversible; susceptible of turning either way.

VERTEBRA, _n._; pl. _vertebræ_. Any bone of the spine; any one of the backbones.

VER´TEBRAL, _a._ Pertaining to the backbone.

VERTEBRARTE´RIAL (_canal_), _a._ for _n._ Passage for an artery through several cervical vertebræ.

VER´TEBRATE, _a._ Having a backbone; also, used substantively for an animal with a backbone.

VER´TEX, _n._ Crown; highest central portion of pileus.

VESCIC´ULA SEMINA´LIS, _n._ A structure, imperfect or wanting in birds, for storage of semen.

VESTI´TUS, _a._ or _n._ Clothed, i.e. feathered. Clothing, i.e. plumage; as, _vestitus nuptialis_, breeding plumage.

VEXIL´LUM, _n._ Rhachis and web of a feather taken together; all of a feather excepting _calamus_.

VIBRIS´SA, _n._; pl. _vibrissæ_. Bristly or bristle-tipped feather about the mouth of a bird.

VIC´TUS, _n._ Food; diet.

VIL´LI, _n. pl._ Soft papulous projections of membrane.

VIS´CERAL, _a._ Pertaining to the viscera.

VIS´CUS, _n._; pl. _viscera_. Any interior organ of the body, but especially of the digestive system. The stomach is a _viscus_; the intestines are _viscera_.

VI´SUS, _n._ Vision; eyesight.

VI´TELLINE, _a._ Pertaining to the vitellus.

VI´TELLINE MEM´BRANE, _n._ An envelope of the vitellus.

VITEL´LUS, _n._ YOLK (which see).

VIT´REOUS, _a._ Glassy; said of the humor in the back chamber of the eye.

VIT´TA, _n._ Broad band of color.

VO´MER, _n._ A bone of the skull, lying at the base, in the median line, in advance of the sphenoid. Also, the peculiarly shaped and enlarged last bone of the tail, or pygostyle.

W.

WASHED, _a._ As if overlaid with a thin layer of different color.

WAT´TLE, _n._ A naked, fleshy, and usually wrinkled and highly colored skin hanging from the chin or throat, as in the cock and turkey.

WEB, _n._ The vane of a feather, on either side of the rhachis.

WEDGE-SHAPED, _a._ See CUNEATE.

WHIS´KERED, _a._ Having lengthened or bristly feathers on the cheeks.

WING, _n._ (73.) See ALA.

WING, BEND OF. (77.) See FLEXURA.

WING-COVERTS, _n. pl._ (83.) See TECTRICES.

WOLFF´IAN BODIES, _n._ Certain organs of the embryo associated with the uro-genitals.