Part 183

UPPER PARTS. (5.) See NOTÆUM.

UPPER TAIL-COVERTS. (72.) See CALYPTERIA.

UPPER WING-COVERTS. (84.) See TECTRICES.

URÆ´UM, n. Hinder half of a bird. (8.) (Little used.)

URE´A, n. A certain component of urine.

URE´TER, n. Tube conveying urine from kidney to cloaca.

URE´THRA, n. Groove in penis for direction of the discharge.

U´RINARY BLADDER, n. A certain compartment of the cloaca, in some birds, is so named.

U´RINE, n. Liquid excretion of the kidneys, in birds voided more or less mixed with the fæces.

URO-GEN´ITAL or GEN´ITO-U´RINARY, a. Said of organs common to the two offices implied in the words, or of such organs regarded as associate parts.

UROHY´AL, n. Median backward process of the hyoid bone.

UROPYG´IUM, n. Rump. (60.)

U´TERUS, n. Womb. Wanting in birds; but a lower tract of the oviduct where the eggshell is formed has been loosely so called.

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.