V

Vagina. * -
* In some insects (Thysanura, Ephemera), the vagina is wanting, and both the oviducts open direct on the postero-ventral surface of the body.
The short passage formed by the two oviducts uniting, which opens to the outside through a special sclerite situated between the seventh and eighth sternites of the abdomen. (L. a sheath.)

Vagina. - The jointed sheath of the promuscis. The bivalve coriaceous sheath of the spicula (Say). (L.)

Vaginal. - Pertaining to, or resembling a sheath; pertaining to the vagina.

Vaginate. - Sheath-like.

Vaginopennous. - Having the wings covered with a hard sheath; sheath-winged. (L. vagina, and penna, a wing.)

Vagus. - The median nervous cord connecting the three unpaired ganglia, constituting the visceral system of insects. (Newport.) (L. vagus, wandering, vagrant.)

Vagus ganglion. - A minute elongated ganglion situated between the aorta and the œsophagus, and which constitutes the termination of the recurrent nerve.

Vagus nervous system. - The sympathetic nervous system, consisting of the arched nerves, frontal nerve, pharyngeal nerve, recurrent nerve, stomogastric nerves, and the vagus ganglion.

Valvæ. - The valves; two lateral laminæ which cover the ovipositor when it is unemployed. (L.)

Valvate. - Possessing or resembling a valve. (L. valva, a valve.)

Valve. - A lid or cover to an aperture, so formed as to open a communication in one direction, and close it in another. (L. valva.)

Valvula. - A corneous piece covering the instruments of suction above; a little valve. (L. diminutive of valva.)

Valvulæ. - The podical plates. (Burmeister.)

Valvule. - A small valve-like process.

Variole. - A pit, or poc-like mark. (Fr. From L. varius, various.)

Variolate, Variolose. - Pitted, poc-marked. (L. varius.)

Vas deferens (Vasa deferentia). - Male organs of reproduction; two in number, which unite to form a single duct (this duct may be absent, and the vasa deferentia then open separately). Each widens posteriorly to form a vesicula seminalis. (L. vas, a vessel, and deferens, bearing down.)

Vasiform. - Vessel-shaped, resembling somewhat a cup or jug in shape. (L. vas, a vessel, and forma, shape.)

Vellum. - A membrane; usually seen attached to some calcaria. (Fr. vélin, from L. vitulus, a calf.)

Velum penis. - The name given to the penis of the locusts. (Acrydiidæ.) (L. a covering, and penis.)

Velutinous. - Velvet-like, covered with very thick short upright hairs. (Ital. veluto.)

Vein. - A tubular vessel which receives the blood or vital fluid and conveys it to the heart and circulating centres. (L. vena, a blood vessel.)

Vena. - A vein. (L.)

Venæ longitudinales. - The longitudinal veins of the wing, which are connected to each other by the transverse veins. (L.)

Venose, Venous. - Painted with lines that branch like veins. (L. vena.)

Vent. - The anus. - (fent, from O.F. fente, a slit.)

Venter. - The belly, the lower or prone part of the abdomen. (L.)

Ventrad. - An abbreviated form of ventrally, or ventral.

Ventral. - Pertaining to the belly, or lower surface. (L. venter.) [PM]

Ventral nerve trunk. - A small inconspicuous nerve trunk originating from the ventral side of the third abdominal ganglion, extending lateroventrally, and sending off branches which innervate the ventral muscles.

Ventral segments. - The transverse segments of the belly. They include the elastes, when they are present. (L. ventralis, from venter, the belly.)

Ventral sympathetic system. - [See Superadded nervous system.]

Ventral tube, or sucker. - A more or less simple tubercle, divided into two halves by a septum, and situated under the anterior abdominal segment of the Collembola. The tube varies in construction in the different genera.

Ventricle. - A small cavity in the body. (L. ventriculus, a belly, stomach.)

Ventricose. - Cylindrical in form, distending suddenly into a large cavity as if filled with air. (Low L. ventricosus, from L. venter.)

Ventricosus. - The term given to the gullet when it dilates into a large bag or crop before its union with the stomach, and detains the food in its passage to that organ. (L.)

Ventricular ganglion. - A triangular nerve centre which lies on the crop, and is connected with the frontal ganglion by the recurrent nerve. (L. ventriculus, and ganglion.)

Ventriculus. - [See Stomach.]

Vermicular. - Resembling a worm. (L. vermes, worms.)

Vermiculate. - Covered with tortuous, irregular, sinuate, worm-shaped markings or striæ. (From L. vermes.)

Vermicule. - A little worm or grub. (L. vermes.)

Vernantia. - Moulting; the shedding of the skin or exuvia. (From L. vernans, from ver, spring.)

Verriculate. - With thick-set tufts of parallel hairs. (L. verres, boar.)

Verruca. - A wart. (L.)

Verruca. - A small flattish wart-like prominence. (L.)

Verrucose, Verrucous, Verruculose. - Covered with wart-like prominences. (L. verruca.)

Versatile. - (Head.) When it can be freely moved every way. (L. versor, to turn.)

Versicolorous. - Of various colours. (L. versi, perf. of vergo, to turn; and color, colour.)

Vertex. - The vertex, the upper flattened portion of the head, upon which very generally the ocelli are situated. (From L. verto, to turn.)

Vertical. - Perpendicular. (L. verto, to turn.)

Vertical. - (Motion.) When it is up and down.

Vertical margin. - The limit between the frons and the occiput of Diptera. (Loew.) (Fr. vertical, from L. verticalis, from vertex and margin.)

Verticillate. - Are those antennæ, the joints of which are surrounded, at equal distances, with stiff hair. (Trichopterygidæ.) (L. verticillatus, from verto, to turn.)

Verticillate. - Placed in whorls. (L. verto.)

Vesicant, Vesicatory. - Raising a blister (applied to Lytta, Mylabris, etc.) (L. vesica, a blister, or little bladder.)

Vesicle. - A little bladder, or portions of the inner membranes, separated to form small bladders; any small membranous cavity or cell. (L. vesica.)

Vesicula seminalis. - Two tufts of white glands holding the spermatozoa, and which connect with the vasa deferentia. (L. vesica; and semen, seed.)

Vesicular, Vesiculous. - Pertaining to, or consisting of vesicles; full of interstices; having small bladders or glands on the surface. (L. vesica.)

Vibratile. - (Motion.) When there is a constant oscillation of any part; adapted to, or used in vibratory motion. (L. vibro, to vibrate.)

Villi. - Fine small fibres or hairs. (L. villus, hair.)

Villosate. - Covered with long hairs. (L. villus.)

Villose, Villous. - Covered with long, loosely set hairs; covered with hairs which give a woolly appearance to the part; covered with soft dense hairs. (L. villus.)

Violaceous. - Violet coloured, a mixture of blue and red. (L. viola, a violet).

Viscera. - The contents of the head, thorax, and abdomen. (L. viscus, an intestine, an entrail.)

Viscid. - Covered with a resinous or greasy matter. (Fr. viscide, from L. viscidus, clammy.)

Viscous, Viscid. - Sticky like bird lime. (L. viscosus, from viscum, bird-lime.)

Visual organ. - The lens of the eye; the crystalline humour of the eye. (Boas.) (L. visum, to see, and Gr. ergon, a work.)

Vitelline membrane. - The thin inner yolk-like membrane of the egg. (L. vitellus, the yolk of of an egg; and membrane.)

Vitellinus. - Yellow, with a slight tinge of red. (L. vitellus.)

Vitreous-body or cell. - The jelly-like mass contained in the visual organ. (L. vitrum, glass.)

Vitta. - A longitudinal coloured stripe. (L. a band.)

Vitta frontalis. - [See Frontal stripe.]

Vittate. - Possessing vittæ.

Viviparous. - Producing young in a living state; opposed to oviparous. (L. vivus, living, and pario, to bring forth.)

Volsellæ. - The median pair of the genital appendages of Ants. (L. volsella, tweezers.)

Vulva. - The orifice of the oviduct. (Packard.) (L. the belly, the womb.)