VER 



VER 



13. Equitant, where the parts overlap 

 each other parallelly and entirely, without 

 any revolution, as the leaves of iris. 



14. Reclinate, when the parts are bent 

 down upon their stalk. 



15. Circinate, when the parts are rolled 

 spirally downwards, as the fronds of 

 ferns. 



16. Falvate, when the parts are applied 

 to each other by the margins only, as the 

 petals of umbelliferous plants, the valves 

 of a capsule, &c. 



17. Quincuncial, when the parts are 

 five in number, of which two are exterior, 

 two interior, while the fifth covers the 

 interior with one margin, and has its 

 other margin covered by the exterior, as 

 iri the rose. 



18. Contorted, when each part is 

 oblique in figure, and overlaps its neigh- 

 bour by one margin, its other margin 

 being, in like manner, overlapped by that 

 which stands next to it, as in apocy- 

 naceae. 



19. Twisted, the same as contorted, 

 except that there is no obliquity in the 

 form or insertion of the pieces, as in the 

 petals of oxalis. 



20. Alternative, when, the pieces being 

 in two rows, the inner is covered by the 

 outer in such a way that each of the ex- 

 terior rows overlaps half of two of the 

 interior, as in liliaceous plants. 



21. Vexillary, when one piece is much 

 larger than the others, and is folded over 

 them, they being arranged face to face, 

 as in papilionaceous flowers. See Vex- 

 illum. 



22. Cochlear, when one piece, being 

 larger than the others, and hollowed out 

 like a helmet or bowl, covers all the 

 others, as in aconite, some species of 

 personate plants, &c. 



VERNIER. A small moveable scale, 

 running parallel with the fixed scale of 

 a quadrant or other instrument, and 

 having the effect of subdividing the 

 divisions of that instrument into more 

 minute parts. Its name is derived from 

 that of its inventor. See Nonius. 



Vernier, chromatic. An instrument 

 inve,nted and so named by Dr, Brewster, 

 and employed for measuring, by com- 

 parison, very minute variations of tints. 



VERRU'CiE {verruca, a wart). Warts, 

 or sessile glands, produced upon various 

 parts of plants, and extremely variable 

 in figure. They are the cellular glands of 

 Mirbel. As they occur on the skin of 

 the seed, they are the seminal spongioles 

 of De CandoUe. 

 365 



VE'RSATILE {versatilis, that turns 

 easily). Oscillating; adhering slightly by 

 the middle, so that the two halves are 

 nearly balanced, and swing backwards 

 and forwards; a term applied to the 

 anthers of plants, when they are attached 

 to the filament by a single point of the 

 connective, as in all true grasses. 



VERSED AND SUVERSED SINE. 

 The versed sine of an arc is that portion 

 of the radius intercepted between the 

 sine and the extremity of the arc. The 

 suversed, or supplemental versed, sine is 

 the difference between the versed sine 

 and the diameter. 



Etymology. '* The terra sine (the Latin 

 word sinus meaning the bosom) has been 

 the object of much discussion. It was 

 at one time looked on as a barbarism 

 from the Arabic ; and some endeavoured 

 to substitute semissis inscriptce, the half 

 of the chord, for it. Others again thought 

 that it was a corruption of S. Ins., the 

 abbreviation of the above. Dr. Hutton 

 asserts that the Arabic word jeib, which 

 is used for the trigonometrical sine in 

 that language, also means the bosom in 

 common language ; and we have been 

 told that this is correct : if so, the Latin 

 sinus is only the literal translation of the 

 Arabic. The arc representing a bow 

 (from which it gets its name), half of the 

 string, which represents the sine of half 

 the arc, would come against the breast of 

 the archer. The versed sine (sinus ver- 

 sus, or turned sine) was called the sagitla, 

 or arrow." — Pen. Cycl. 



VERTEBRA'TA {vertebra, a joint of 

 the back-bone). A large division of the 

 Animal Kingdom, including all those 

 species which are furnished with a back- 

 bone, or vertebral column, as the mam- 

 malia, birds, reptiles, and fishes. These 

 are the Myelencephala of Owen, the Spi- 

 nicerebrata of Grant. 



VERTEX. Literally, the top or sum- 

 mit of any figure. In Astronomy, it de- 

 notes that point in the heavens which is 

 directly over our heads, called the zenith. 

 In Geometry, it is the apex, or upper 

 point, of a triangle. In conic sections, it 

 is the point through which the genera- 

 ting line of the conical surface always 

 passes. The vertex of a curve is the 

 point in which the diameter meets the 

 curve. 



VERTICAL {vertex, the top). Per- 

 pendicular ; being at right angles to any 

 body. A vertical circle, in Astronomy, 

 is a great circle perpendicular to the 

 horizon, and passing through the zenith 

 R3 



