VES 



VES 



and nadir of any place. A vertical line 

 has the same meaning. A vertical 

 plane, in conies, denotes a plane passing 

 through the vertex, and parallel to the 

 plane of the section. 



VERTICAL CIRCLES. This name 

 is applied, in Nautical Astronomy, to 

 great circles drawn on the hollow sphere, 

 passing through the zenith of any place. 

 That particular vertical circle which 

 passes through the east and west points, 

 is called the prime vertical; the angle 

 contained between a vertical circle pass- 

 ing through a heavenly body and the 

 celestial meridian opposite to a place, is 

 called its azimuth. 



VERTICILLA'STER {verticillus, a 

 whorl). A botanical term applied by 

 Hoffmansegg to the cyme when reduced 

 to a very few flowers. It constitutes the 

 normal form of inflorescence of the La- 

 biatae, or Mint tribe, in which two verti- 

 cillastri are situated opposite to each 

 other in the axils of opposite leaves. By 

 Linnaeus, the union of two such verti- 

 cillastri was called a verticillus, or whorl ; 

 and by others, with more accuracy, a 

 verticillus spurius, or false whorl. By 

 Link, this form of inflorescence is called 

 a thyrsula. 



VERTICI'LLUS {verto, to turn). Lite- 

 rally, a little whern, a whorl, an axis, or 

 spindle. This term is applied, in Botany, 

 to that arrangement of leaves upon the 

 stem, in which more than two of them 

 are opposite to one another, or are on the 

 same plane, as in Galium. The natural 

 order Galiaceae has, in fact, been named 

 Stellatce, from the stellate or whorled 

 arrangement of the leaves. 



VESICLE {vesicula, dim. of vesica, a 

 bladder). A small, circular, inclosed 

 space, like that contained by a little 

 bladder. Hence, the term vesicular tissue 

 is applied to one of the elementary 

 tissues of plants, generally consisting of 

 little bladders or vesicles of various 

 figures, adhering together in masses. 

 This is also called cellular and utricular 

 tissue. 



VESICULA AMNIOS. Vesicula col- 

 liquamenti. The name given by Mal- 

 pighi to the quintine, or fifth integument 

 occasionally found in the ovule of plants. 

 This is called by other writers, sac of the 

 embryo, additional membrane, &c. A 

 very delicate thread, called the suspensor, 

 descends from the summit of the ovule 

 into the quintine, and bears at its ex- 

 tremity a globule which is the nascent 

 embryo. 

 366 



VESPERTILIO'NID^. The Bat 

 tribe; a family of insectivorous Cheiropte- 

 rans, characterized by peculiarities of the 

 nasal appendages. In the Rhinolophina, 

 or Horse-shoe bats, the nasal appendages 

 are complicated and membranaceous ; 

 in the Phyllostomince, or true Leaf-nosed 

 bats, the appendage is simple, fleshy, 

 solitary or double ; in the Pteropinet, or 

 Simple-nosed bats, in the Noctilionince, 

 or Bull-dog bats, and in the Vesper- 

 tilionincB, or True bats, there is no nasal 

 appendage at all. 



VE'SPID^ {vespa, a wasp). The 

 Wasp tribe ; a family of hymenopterous 

 insects, distinguished from all other spe- 

 cies of the order by having their wings 

 folded, when at rest, through their entire 

 length. 



VESSELS, MILK. AND TURPEN- 

 TINE. Vasa propria. These names 

 were given by Grew to certain cavities 

 in plants, formed by expansion of the 

 simple "intercellular spaces," and filled 

 with the peculiar juices of the plant, as 

 with milk in the poppy, with turpentine 

 in terebinthus, &c. These are the acci- 

 dental reservoirs and the ccecal reservoirs 

 of De CandoUe. See Vittcc. 



VESSELS, STRANGULATED. Vasa 

 moniliformia, vel vermiformia. A variety 

 of vessels found in plants, characterized 

 by a moniliform, or necklace-like, appear- 

 ance, occasioned by irregular compres- 

 sion, or strangulation, when growing in 

 knots or parts which are subject to an 

 interrupted mode of development. By 

 the French, these vessels are termed 

 vaisseaux en chapelet or Strangles. They 

 are considered to be young spiral vessels, 

 which, instead of lengthening, grow toge- 

 ther by their ends. 



VESSELS, VITAL. Vasa opophora. 

 A peculiar form of vessels in plants, con- 

 sisting of branched anastomosing tubes, 

 lying in no definite position with regard 

 to other tissue, said to be contractile, 

 though destitute of valves in their in- 

 terior. They occur in the milky cicho- 

 raceous plants, in the root of dandelion, 

 &c. The larger trunks were called by 

 Schultz vasa expansa ; the fine ramifica- 

 tions, vasa contracta. From their con- 

 taining a peculiar liquid, called latex, 

 they have been termed laticiferous tissue, 

 and, more recently, cinenchyma. 



VESTA. A telescopic planet, situated 

 in the solar system between Mars and 

 Jupiter, discovered by Dr. Olbers, of 

 Bremen, in 1807. She describes her orbit 

 in three years, sixty-six days, four hours. 



