LEMMA 



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LENTICULAR 



Lemma (lem'-ah) [Mu/xa, peel: pi., Lemmata]. A 

 general name for a limiting or ensheathing membrane ; 

 e. g., neurilemma, sarcolemma, etc. It is mostly 

 used in composition. In embryology, the outer layer 

 of the germinal vesicle. 



Lemnian Earth (Jem' -ne-an) \7J](ivioq, Lemnian]. A 

 variety of reddish kaolin, originally found in the Isle 

 of Lemnos ; a kind of bole (a. v.) used as an astrin- 

 gent; also, as a detergent, like fuller's earth; Lem- 

 nian bole. See, also, Ocher. 



Lemniscus (lem-nis' -kits) [Xr/fivimcoc, fillet]. I. A 

 ribbon-like appendage. 2. Fillet; a triangular area 

 on the lateral slope of the mesencephal, in which the 

 fibers run approximately cephalo-dorsad. It is dorso- 

 . cephalad of the demarcation-line of the pons, and con- 

 stitutes the most ventral part of the tegmentum. Sev- 

 eral divisions are made ; e. g. , inferior, lateral, and 

 median or superior lemniscus. 3. In biology, the 

 name given by Rudolphi to a glandular, filiform organ, 

 pendent, on either side of the proboscis-sheath, in 

 the anterior body-cavity of Echinorhynchus. Dujardin 

 considers it to be of the nature of a salivary gland. 



Lemon (Jem' -on). See Limon. 



Lemonade (lem-on-ad') [limon, lemon]. An acidulous, 

 refrigerant drink made from the juice of lemon. L., 

 Sulphuric Acid, a solution of sugar in water con- 

 taining sulphuric acid. It is used in lead manufac- 

 tories to prevent lead-poisoning. 



Lemoparalysis (Je-mo-par-al' -is-is) \Jkai[i6c, gullet ; 

 irapdXvaig , palsy]. Paralysis of the esophagus. 



Lemostenosis (le-mo-ste-no'-sis) ['Aai/udg , gullet ; ote- 

 vuaiq, stricture]. Constriction of the pharynx or 

 esophagus. 



Lendigerous (Jen-dif '-er-us) [lens, a louse's egg ;gerere t 

 to bear]. Bearing or having vesicles. 



Lenhossek, Bundle of. The ascending root of the 

 vagus and glosso-pharyngeal nerves. 



Leniceps (len'-is-eps) [lenis, mild ; capere, to seize]. 

 A form of obstetric forceps, with short handles ; it is so 

 called because it was designed to be safer in use than 

 the ordinary forms. 



Lenient (Je'-ne-ent) [leniens, softening]. I. Lenitive; 

 emollient. 2. An emollient medicine or application. 



Leniment (Jen' -im-ent) [lenire, to soothe]. A liniment 

 or soothing application. 



Lenitis (Jen-i'-tis). A term for phlegmonous gastritis, 

 or suppurative inflammation of the areolar tissue of 

 the stomach. 



Lenitive (len' '-it-iv) \Jenitivus, soothing]. Emollient 

 or demulcent ; laxative or aperient. 2. An emollient 

 remedy or application ; an aperient or mildly cathartic 

 agent. L. Electuary, confectio sennte. 



Lens (Jenz) [L. , a lentil]. A regularly-shaped piece 

 of glass or crystal for the refraction of rays of light. 

 The crystalline lens of the eye. L., Achromatic. 

 See Achromatic. L., Apochromatic. See Apo- 

 chromatic. L., Astigmatic. See L., Cylindric. 

 L., Astigmatic, of Stokes, an apparatus con- 

 sisting of two plano-cylindric lenses, one concave, 

 the other convex, the two of equal focal distance ; 

 it is used in the diagnosis of astigmatism. L., 

 Biconcave (negative or minus ( — ) lens), a thick- 

 edged lens having concave spheric surfaces upon 

 its opposite sides ; it is used in spectacles to cor- 

 rect myopia. L., Biconvex {positive or plus (4-) 

 lens), a thin-edged lens ; it has two convex surfaces, 

 and is used to correct hyperopia. L., Bifocal. See 

 Bifocal. L., Cicatricular, a lenticular body in the 

 ovum formed by the junction of the germinal vesicle 

 and the non-germinal layer of the ovum. L., Con- 

 vergent or Converging, a double convex or plano- 

 convex lens that focuses rays of light. L. , Crystalline, 



the lens of the eye, situated immediately behind the 

 pupil. L., Cylindric (either minus or plus), one 

 ground upon a cylindric tool, i. e., one with a plane sur- 

 face in one axis and a concave or convex surface in the 

 axis at right angles to the first. L., Decentered, one 

 in which the optic center is not opposite the pupil of 

 'the eye. L., Dispersing, a name for a concave lens. 

 L. -paper, a soft absorbent paper much used for clean- 

 ing lenses ; it is also known as Japanese filter-paper. 

 L., Periscopic, one with concavo-convex or convexo- 

 concave surfaces, the opposite sides being of different 

 curvatures ; it is used to avoid spheric aberration, and 

 to gain a greater field of clear vision ; such lenses are 

 called meniscus lenses. L., Plano-concave, Plano- 



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Different Forms of Spheric Lenses. 

 1. Biconvex lens. 2. Plano-convex. 3. Concavo-convex, or 

 convergent meniscus. 4. Biconcave 5. Plano-concave. 

 6. Convexo-concave, or divergent meniscus. 



convex, Plano-cylindric, have a plane surface upon 

 one side and a curved surface upon the reverse side. 

 L., Prismatic, a triangular bar of glass. L., Spheric, 

 one whose curved surface, either concave or convex, is 

 a segment of a sphere, in contradistinction to a cylin- 

 dric lens. L., Sphero-cylindric, one with a spheric 

 surface upon one side, and a cylindric surface upon the 

 reverse, used for the correction of either myopia or 

 hyperopia, associated with astigmatism. See Spectacle- 

 lenses. L.-star, the stellate figure seen on the pos- 

 terior surface of the crystalline lens. L., Test or 

 Trial, one of a set of lenses employed in determining 

 refractive errors. 



Lenticel (Jen' -tis-el) \lenticella ; dim. of lens, lentil]. 

 Any one of the little mucous follicles or crypts at the 

 base of the tongue ; any lenticular gland. In biology, 

 a lens-shaped collection of cells ; applied to the di 

 new bark and to certain glands. 



Lenticellate (len-tis-el'-dt) \lenticella ; dim. of lens, 

 lentil]. Having lenticels. 



Lenticonus (Jen-tik-o' '-nus) [lens, a lens ; conns, a 

 cone]. A rare, usually congenital, anomaly of the 

 lens in which there is a conical prominence upon its 

 anterior, or more rarely upon its posterior, surface. 



L'enticula (Jen-tik'-u-lah), Lenticule {len'-tik-Ul ) [L.J 

 dim. of lens, lentil: pi., Lenticulie\. 1. San 

 Lentigo. 2. A mass of gray matter in the brain mini- 

 ated in the hemicerebral wall, between the caudatuM 

 and the cortex. It consists of three zones know 

 articuli, all more or less striated, the ental the small- 

 est, and the ectal, also called putamen, the largest 

 The latter is of a deeper reddish-gray color than the 

 two mesal divisions, which together air termed 

 globus pa lliilus. 3. In biology : (a) a spore 

 (o) a freckle. 



Lenticular {len-tik' -u-lar) [lenticularis ; lens, a lentil]. 

 Pertaining to, or resembling, a lens ; also a descrip- 

 tive term applied to an instrument with a curved cut- 

 ting-edge for removing the rough edges of hone made 

 by the trephine. L. Ganglion. See Ganglia, Tout 

 of. L. Nucleus, the lenticula, a. v. 



