ANGLE OF REFRACTION.

GO, an incident ray pa ing from a rarer to n denser medium; OH, the retracted ray; A0G, the a, of incidence; 0B, the a. of refraction; £9, an incident ray pa irg from a ate lo pigs med i an Cras making with the perpendicular io the surface of Cantacto) the wedia an a,, FOB, greater than the limiting a., when it an der goes total reflection at O, take ing the directlon OD. O. no: 02, not; 03, whole: Th, thin; Th?, the: U, like 00 in too; U2, blue; U?, lull; U4, full; US, urn; U®, like ü (German), 37 place, but the light-ray will undergo total reflection at the surface of contact of the two media. [B, 21, 22, 166.) Cf. Refracting a.— A’s of Segond. Two a's prcpoeed by Segond, having their apices at the basion: 1, the facial, included between a line running to the supra-orbital point and another running to the lower border of the upper jaw; 2, the cerebral, included between the plane of the occipital foramen and a line running to the supra-orbital point. (L, 149.]—A. of supination of the hand, A. of supination of the radias. The extent (about 180°) to which the hand can be supinated. [L, 149.]—A. of the clivus. See Condylar a.—A. of the crow See Internal a. of the ilium.—A. of the eye. See ANGULUS oculi.— A. of the haunch. See External a. of the ilium.—A. of the ilium. The crest of the ilium in the domestic animal {L, 13.J—A. of the Ischio-pubic arch. The a. at which the ischio-pubic rami tend toward each other, {J, Wood (L, 133).J—A. of the jaw. See A. of the lower jaw.—A. of the lips. See ANGULUS or is.—A. of the lower jaw, A. of the mandible. Fr., a. de la mâchoire inférieure. Ger., Unterkieferwinkel. It., angolo dell’ o o mas cell are inferiore. Sp., dngulo de la mandibula. The a. formed by the lower margin of the body of the bone with the posterior margin of the ramus. [L, 41.]—A. of the mouth. See ANGULUS or is.—A. of the neck. See A. of the nucha.—A. of the neck of the femur. The a. formed by the neck of the bone with the shaft; obtuse in infancy, diminishing with age, and le in women than in men, averaging in adults between 125° and 130°. [A, 5.]—A. of the nose. Fr., a. du nez. The a. at which the nose joins the cheek, [L, 183.]—A. of the nucha. Fr., a. del a nuque. The reentrant a. formed by the junction of the nucha with the neck. [A. 385.—A. of the pubes. Fr.… a. du pubis. Ger., Schamwinkel. It., angolo del pu The a. formed by the junction of the two pubic bones. [A, 301,]—A’s of the uterus. Fr., a’s tubaires. It., angoli dell’ utero. Pa dngulos tubdricos del utero. The sharp lateral terminations of the two cornua, corresponding on either side to the locality at which the oviduct enters the uterus. [A,:85.]— A. of torsion. Fr., a. de torsion, The degree to which the shaft or body of a bone is twisted. { 143, 149, 150.]—A. of vision. See Optic a.—A. of Vogt. An a, having its apex at the nasion, formed by a line running to the basion and another running to the alveolar point. [L, 149.|—A. orbito-alvéolo-condylien (Fr.), See Orbitoalveolo-condylar a.—A. par iétal (Fr.). See Parietal a. and A. de flexion cranienne.—A. principal (Fr.). See Principal a—A.- rapporteur (Fr.). See PROTRACTOR.—ÀÂ. sacro-vertébral (Fr.). See Sacro-vertebral a.—A. saillant (Fr.). See Acres (1st def.). —A. sphénoïdal (Fr.). See Spheugidat a.—A. symphysien (Er). See Symphyseal a.—A’s tubaires (Fr.). See A's of the uterus—A. visuel (Fr.). See Optic a.—A. xiphoïdien (Fr.). See Xiphoid a—Anterior a. of the ilium. See External a. of, the ilium—Anterior a. of the scapula. See Cervical a. of the scapula.—Anterior parietal a. See Parietal a. (Ist def.). —Autero-external a. of the ischium. In the domesticated animals, the ppoeariog extremity of the supra cotyloid crest, limited by a small transverse fi ure which separates it from the external border of the bone and an excavated diarthrodial facet which makes a pete of the cotyloid cavity. [L, 13.|—Antero-internal a. of the ischiumn. ‘That portion of the ischium which, in the domesticated animals, fog emir with the posterior a. of the pubes, closes in the obturator foramen inwardly. [L, 13,|—Aurleulara’s. Fr., a’s auricula ires [Broca]. Those cephalic a’s that have their apices at Broca’s auricular point (the centre of the external auditory meatus). [L.]—Auriculo-cranial., Fr., a’s auriculo-craniens [Broca]. Those auricular a's the sides of which pa through the cranium. [L.)—Auriculo-facial. Fr., a's auriculo-faciaux [Broca]. ose auricular a’s the sides of which ‘THE PRINCIPAL CEPHALIC POINTS. (AFTER FLOWER [L, 142].) A, the alveolar polnt; S, the enbnasal point;, the nasion; Op, the ophryon; Bg, the bregma; Z, the lambda; O, the occipital point; the inlon; À, the baslon, pa through the face. [L.]—Auriculo-frontal a. Fr., a. auricula ire frontal. See Frontal a.—Auviculo-oceipital a, Fr., a. auriculo-occipital. The suboccipital and supra-occipital a’s combined. [Bertillon (L, 87).j—Auriculo-parietal a. Fr., a. auriculo-par iétal. The parietal a. of Broca. [L.]—Bas i facial a. The a. formed by the basicranial axis (a line drawn from the basion to the middle of the anterior border of the cerebral surface of the sphenoid bone) and the bas i facial axis (a line drawn from the same oint of the sphenoid bone to the alveolar point). [L, 142.]—Basiar a. Fr., a. basilaire [Broca]. An a, included between two lines ——T \ # L; H 7 u “ ‘THE PRINCIPAL CEPHALIC ANGLES. (AFTER BRocA [L, 87].) ‚A, the alvoolar point; E, the bate of the cubnatel spine; R, the naso-frontal entnreg G, the median point of the plane of the roofs of the orbits, or glabella, separating the face from the cranium; F, the bregma; V, the vertex; Æ, the basion; Z,the lambda; O, the auricular Point of Broca; P, t tal lis opisthion; w, w’, the inion, fonnd above or below the horizonine H, Hl; AOG, the orbito-facial angle; GOF, the frontal angle; FOL, the parietal angle; LOP, the occipital angle; LOw’, the supra-cecipital angle; «OP, the sub-occipital angle} OEG, the tacial angle of G, Cuvier; OAG, the facial angle of Cloquet; GOw’, the cerebral angle, meeting at the basion, one being drawn from the nasion and the other from the Gye {L, 143.]—Bi-orbital a. Fr., a. bi-orbitaire [Broca]. e a. formed by the intersection of the axes of the orbits. [i,, 143.]-Cephalic. Fr., a’s céphaliques. Ger., Kopfwinkeln. A general term for the cranial and facial a’s; employed as standards of comparison between different races of men and between man and other animals. [{L.]—Cerebellar a. Fr., a. cérébelle See Suboccipital a.— Cerebral a. Fr., a. cérébral. One made up of the frontal, parietal (of Broca), ant supra-occipital a's. [L, 143.]—Cervical a. of the scapula. In the domesticated animals, the fea of union of the anterior and ‘superior borders of the scapula. [L, 13.,)—Condylar a. An a. formed by the plane of the occipital foramen with that of the bas i- 5 CRANIAL ANGLES. (AFTER BERTILLON [L, 87].) ‚E tho naslon BF, the plane of the oceipital foramen; Æ the base of the nasal spine B, the basion; P the opisthion; S, the centre of the traneverse groove of the optic commi ure; FEB, the nasal angle of Welcker; RAP, the basilar angle of Broca; RPB, the occipital angle of Broca; RSB, the sphenoidal angle. lar groove. [Ecker (L, 149).]—Co-orbital a. Fr., a. co-orbitaire. An a. formed by the intersection of the anatomical plane of the head and the bi-orbital plane. [Broca, “ Bull, de la Soc, d’anthrool.,” Oct. 10, 1878 (L).]—Corono-facial a. Fr., a. corono-facial [Gratiler It., angolo corono-facciale. Ana. formed between the racial line of canner and a plane pa ing through the coronal suture. [* Bull. de la Soc..,” ii, p. 255 (L).]—Costal a. See Subcostal a.—Cotyloid a. In domesticated animals, that portion of the ilium situated between the supra cotyloid crest and the cotyloid foramen. [L, 13.] See also External a. of the pubes— Cotyloid ean a. of the ischinm. See Antero-erternal a, of the ischium.—Cranial. Fr., a’s craniens, Cephalic a's corresponding to the auricular a’s, but having their apices at the anterior border of the occipital foramen. [Bertillon (L, 87).)—Craniofacial a, Fr., a. cranio-facial. 1. Of Ecker. See Meta facial a. 2. Of Huxley, the a. formed at the middle of the anterior border of the jugum sphenoid ale by a line drawn from the basion and another from the nasal spine. [L, 150.|—Critical a. Syn.: limiting a. The greatest a. which a ray of light pa ing from a denser to a rarer medium can make with the perpendicular to their surfaces of contact without undergoing total reflection. The sine of this a. is the ra rocal of the index of refraction of the denser medium. B, 21] - lomes tic a ted quadrupeds, the union of the rior borders of the scapula. [L, 18.1—Ephippial a. [Welcker]. See Sphenoidal a.—Ethmo-cranial a. See Olfactory a.—External a. of Mulder, An a. formed by the intersection of Camper's facial line and a line running from the bas i-occipital bone to the nasion. [L, 108.]— External a. of the ilium. Fr, «. antériéur de Vos iliaque. In the domesticated quadrupeds, the anterior superior spine of the ilium. [L, 13,)—External a. of the pubes. In the lomes tic a ted quadrupeds, that portion of the pubic bone which forms the chief part of the cotyloid cavity. [la 13.|—Facial a. Fr., a. facial. Ger., Gesichtswinkel. It, angolo facciale. Sp., dngulo facial. 1: Of Camper, an a. formed by the intersection of Cainper's facial line (a line tangent to the most proniiaend part of the forehead and the point of intersection) and a line running from the auricular point to the point of intersection. There is some un- . A. of refraction—Dorsal a. of the scapula, In the osterior and the supe certainty as to Camper’s point of intersection, but it was probably at the subnasal spine. [Bertillon (L, 87).] 2. Of Albrecht Dürer {although doubt has been expre ed as to whether he suggested it), an a. formed by a line tangent to the brow and the lobule of the nose and a line running from the lobe of the ear to the lower part of the nasal septum. [Topinard, ‘* Bull. de la Soc..,” Dee. 7, 1876 (L).] 3. Of G. Cuvier and Geoffroy St.-Hilaire, an a. formed by a line running from the glabella to the lower edge of the nasal septum in the living subject (to the subnasal spine of à skull) and a line running from the auricular point to the latter. |Bertillon (L, 87).] 4. Of Cloquet (Fr., à. facial alvedlaire), an a. formed by a line tangent to the glabella and the alveolar border of the superior maxilla and a line running from the auricnlar point to the latter. P. Broca, ‘* Bull. de la Soc..,” cae 7, 1874 (L).] 5. Of art, the same as that of Cuvier and Geoffroy St.-Hilaire, but having its apex at the nasal spine. [P. Broca, * Bull. de la ‘Soc..,” May 7, 1874 (L).] 6. Of Broca and of Topinard, the ophryo-spinal facial a. (q. v.). 7. Of the Germans (the Munich- Frankfort, or Virchow and Holder's, facial a.), see A. du profil. {L.J—Frontal a. Fr., a. frontal. 1. The a. formed by a line running from the auricular point to the bregma and one running from the auricular point to the glabella. |L, 143.] 2, In birds, the a, formed by the upper line of the beak with the forehead. [A, El —Fronto-glabellar a. Fr., a. frontal glabella ire. The slope ol the forehead. [L, 149, 150.]—Great a. of the eye. Fr., grand a. de l’œil, See ANGULUS oculi intern us—Humeral a, of the scapula. In the dome ticated animals, the head of the bone. [L, 13.] —Hliwischial a. The a. formed by the ischium with the cotylosacral rib of the ilium (oomres ponding: to the mean direction of the ilium). [J. Wood (L, 133).|—Hlio-pubic a. The a. formed in the lower animals between the ilinm and the pubic bone. [J. Wood (L, 183).]—Hio-vertebral a. The a. formed by the ilia and the vertebral column. [L,133.|—Inferior a. of inclination of the pelvis. See A. of inclination of the pelvis.—Inferior a. of the scapula. See Humeral a. of the scapula.—Inio-facial a. Fr, a. inio-facial. It, angolo inio-facciale. A modification of Camper’s facial a. Ta by Des champs; formed hy a line drawn from the inion to the glabella and another drawn from the inion to the symphysis ment i. Grenet speaks of several further modifications, the points taken being the line of the hair on the forehead, the nasofrontal suture, the tip of the nose, the point of the subnasal spine, the border of the superior alveolar proce es, the edges of the incisors (the jaws being closed), and the bottom of the depre ion below the mouth. [Bertillon (L, 87).]—Internal a. of the ilium. In the domesticated animals, the posterior pure ‘ior spine of the ilium. [L, 13.]—Internal a. of the pubes. In the domesticated animals, the a. of the pubes (q. v.).—Internal a. of Walther. The a. formed by a line running from the occipital protuberance to the crista gall i and one running from the glabella to the nasion. [L, 108.|—Interradial a. The a. formed at the junction of the lateral walls of two adjacent ambulacral grooves in the star-fish. [B, 100.] —Liniting a. Fr., a. limite. Ger., Grenzwinkel, See Critical a.— Louis’s a. See ANGULUS Ludovici.—Lumbo-iliae a. The a. formed in some of the lower animals by the sacrum and the iliae wings. [J. Wood (L, a NT a. Fr., a. mandibulaire [Brocal. See À. of the lower jue, Maxillary a. of Camper. An a. having its apex at the point of contact of the upper and lower central incisor teeth, formed by a line running to the ophryon and another running to the most prominent part of the inferior maxilla. [L, 150.]—Meta facial a. Fr., a. méta-facial [Serre]. It., angolo méta-facciale. The à. formed by the pterygoid proce es with the plane of the lower surface of the base of the skull. [Bertillon (L, 87).] —Metre-a. The a.of convergence of the two eyes when both are fixed on an object situated at a distance of 1 metre from each. [Nagel (F).|—Nasal a. Fr., a. nasal. 1. Of Ranke, the a. formed by the horizontal line of the skull (of the Germans) and a line running from the middle of the naso-frontal suture to the middle of the alveolar border just beneath the nasal spine. [** Rev..,” 1884 (L).] 2. Of Welcker and Virchow, the a. formed by a line running from the subnasal spine to the naso-frontal suture and one running from the subnasal spine to the basion. [Bertillon (L, 87).]— Nasal a. of the eye. The inner a. of the eye. [A, 314.|—Nasobasal a. See Nasal a. (2d def.).—Naso-malar a. |Flower.] An a. formed at the base of the nose by the intersection of two lines coming from the outer margins of the orbits; from 130° to 135° in Europe ans, and from 140° to 145° in Mongol i ans. [L, 112.|—Negatlve a. À term applied to the parietal a. of Quat ref ages when It is turned downward. [Bertillon (L, 87).]—Occipital a. Fr, a. occipital. 1. Of Broca, the a. formed by the plane of the occipital foramen with a line running from the opisthion to the root of the nose. [Bertillon (L, 88).] 2. Of Daubenton, see A. of Daubenton. 3, An à. formed at the basion by the basicranial axis and the plane of the occipital foramen. [L, 148.)—Olfactory a, Syn.: ethmocranial a. The a. formed by the basicranial axis with the plane of the cribriform plate of the ethmoid bone. [L, 148.]—Ophryoalveolo-auricular a. See Facial a. (4th Ce pinal facial a. Fr., a. facial omis aire {Broca]. The facial a. of Broca and of Topinard; formed by a line running from the ophryon to the nasal spine and one running from the auricular point to the nasal spine. [L, 143.|—Optie a. Fr.. a. optique (ou visuel). Ger., optische Winkel, Sehwinkel. It, angolo oltico (0 visuale). Sp., dngulo dptico (6 visual). Syn. isual a, The a. included hetween the lines which join the extremities of an object looked at with the posterior nodal point of the eye, or the a. made by the decu ation of lines running from the extremities of any object through the posterior nodal point. [F, 27.|—Orbito-alveolo-condylar a. Fr, a. orbito-alvéolo-condylien, a. alvéolo-condylien [Broca]. The à. formed by the intersection of the horizontal visual plane and a plane tangent to the condyles of the occipital bone and the alveolar proce es of the superior maxilla. [L. 143.|-Orbito-basilar a. Fr., a. orbito-basilaire. An a. formed by the intersection of the bas i facial plane of Barclay and the plane of the orbital axes. [L, 150.) Orbi to-facial a., Orbito maxillary a. Fr., a. orbito-marillaire. An a. formed by a line running from the ana to the auricular point and one running from the alveolar border to the auricular point. [L, 143.]—Orbito-oceipen a. Fr., a. orbito-occipital [Broca]. The a. formed hy the intersection of the bi-orbital plane and the plane of the occipital foramen. {L, 143.]—Or i facial a’s of Barclay. 1. An a. formed by the intersection of Camper's facial line and the plane of mastication, 2. One forined by the intersection of the median anteroa con line of the palatine arch and the median antero-posterior ine of the plane of the lower horder of the lower jaw. [L, 150.]— Palatine a. Fr., a. palatin. It, angolo palatino. A term applied by S. Cuvier At Geoffroy St.-Hillaire to an a. formed by Camper's horizontal facial line (running from the external auditory meatus to just below the nasal spine) and a line on the plane of the alveolar arch. As these lines are generally parallel, no a. is formed, {E. Geoffroy St.-Hilaire and G. Cuvier, * Mag. encyclopéd.,” iv, 1795, p. 459 (L).|—Parietal a. Fr., a. par iétal. It, angolo parietale. 1, Of Quat ref ages, an a. formed by the intersection of two lines drawn one on either side of the head tangent to the most prominent points of the zygomatic arch and the fronto-parietal suture. When the bilateral diameters of the head at these two points are equal, no angle is formed. [Bertillon (L, 87).] See Positive a. and Negative a, 2. Of Broca, an auricular a. formed by two lines running from Broca’s auricular point to the bregma and to the lambda. [L, 143.) See also A. de flexion cranienne.—Pelvic. See A. of inclination of the pelvic canal, A. of inclinafli tion of the pelvis, A. of the ischio-pubic arch, A. of the pubes, Antero-external a, of the ischium, Antero-internal a. of the ischium, Cotyloid a., External a. of the ilium, External a. of the pubes, Ilio-ischial a., Ilio-pubic a., Ilio-vertebral a., Internal a. of the ilium, Internal a. of the pubes, Lumbo-iliac a., Posterior a. of the pubes, Postero-internal a. of the ischium, Sacro-vertebral a., and Vertebroiliac a,—Pelvi-vertebral a. See A. of inclination of the pelvis—Polarizing n. See g À. of polarization.—Positive a. A name iven to the parietal a. of Quat ref ages when it is formed above the vertex. [Bertillon (L, 87).|—Posterior a. of the ilium. See Cotyloid a.—Posterior a, of the pube: hat portion of the puble bone which, in the horse, uniting with the antero-internal a. of the ischium, closes in the obturator foramen in-