HY´PER-O-PI-A. Abbreviated from HY´PER-MET-RO´PI-A (Gr. [Greek: huper], _huper_, beyond, [Greek: metron], _metron_, the measure, and [Greek: ôps], _ops_, the eye). A defect of vision dependent upon a too short eyeball; so called because the rays of light are brought to a focus at a point behind the retina; the true "far sight." IN-CI´SOR (L. _inci´do_, to cut). Applied to the four front teeth of both jaws, which have sharp cutting edges. IN´CUS (L). An anvil; the name of one of the bones of the middle ear. IN-SAL-I-VA´TION (L. _in_, and _sali´va_, the fluid of the mouth). The mingling of the saliva with the food during the act of chewing. IN-SPI-RA´TION (L. _in_, and _spi´ro_, _spira´tum_, to breathe). The act of drawing in the breath. IN-TEG´U-MENT (L. _in_, and _te´go_, to cover). The skin, or outer covering of the body. IN-TES´TINE (L. _in´tus_, within). The part of the alimentary canal which is continuous with the lower end of the stomach; also called the intestines, or the bowels. I´RIS (L. _i´ris_, the rainbow). The thin muscular ring which lies {258} between the cornea and crystalline lens, and which gives the eye its brown, blue, or other color. JU´GU-LAR (L. _ju´gulum_, the throat). The name of the large veins which run along the front of the neck. LAB´Y-RINTH (Gr. [Greek: laburinthos], _laburin´thos_, a building with many winding passages). The very tortuous cavity of the inner ear, comprising the vestibule, semicircular canals, and the cochlea. LACH´RY-MAL APPARATUS (L. _lach´ryma_, a tear). The organs for forming and conveying away the _tears_. LAC´TE-ALS (L. _lac_, _lac´tis_, milk). The absorbent vessels of the small intestines; during digestion they are filled with chyle, which has a milky appearance. LA-RYN´GO-SCOPE (Gr. [Greek: larunx], _larunx_, the larynx, and [Greek: skopeô], _skopeo_, to look at). The instrument by which the larynx may be examined in the living subject. LAR´YNX (Gr.). The cartilaginous tube situated at the top of the windpipe, or trachea; the organ of the voice. LENS (L.). Literally, a lentil; a piece of transparent glass or other substance so shaped as either to converge or disperse the rays of light. LIG´A-MENT (L. _li´go_, to bind). A strong, fibrous material binding bones or other solid parts together; it is especially necessary to give strength to joints. LIG´A-TURE. A thread of silk or other material used in tying around an artery. LYMPH (L. _lym´pha_, spring-water). The colorless, watery fluid conveyed by the lymphatic vessels. LYM-PHAT´IC VESSELS. A system of absorbent vessels. MAL´LE-US (L.). Literally, the mallet; one of the small bones of the middle ear. MAR´ROW. The soft, fatty substance contained in the central cavities of the bones: the spinal marrow, however, is composed of nervous tissue. MAS-TI-CA´TION (L. _mas´tico_, to chew). The act of cutting and grinding the food to pieces by means of the teeth.