FIGURE 2.—_Back View of the Heart and Lungs._—_a_, Larynx. _b_, Trachea. _c_, Right bronchus. _d_, Left bronchus. _e_, Left auricle of the heart. _f_, Left ventricle. _g_, Right pulmonary veins. _h_, Left pulmonary veins. _i_, Left pulmonary artery. _j_, Section of the aorta. _k_, Trunks of the brachio-cephalic veins (those which belong to the arms and head). _l_, The opening of the inferior vena cava.—The sub-divisions of the pulmonary arteries and veins, and of the air-tubes or bronchi, are seen accompanying each other in the left lung in both figures. GLOSSARY AND INDEX. A ABDOMEN (L. _abdo_, to hide). So called from its containing the intestines, &c. ABDUCTOR (L. _abduco_, to draw from). _Abducent._ A muscle whose office is to draw one part of the body away from another. ABSORPTION. The act or process of imbibing or swallowing. ABSORBENTS. Vessels which imbibe, as lymphatics and lacteals. ALBUMEN (L. _albus_, white). Albumen is of two kinds, animal and vegetable: 1. _Animal albumen_ exists in two forms, the liquid and the solid. In the _liquid_ state, it is a thick, glairy fluid, constituting the principal part of the white of egg. In the _solid_ state, it is contained in several of the textures of the body, as the cellular membrane, the skin, glands and vessels.—2. _Vegetable albumen_ closely resembles animal albumen, and has been found in wheat, rye, barley, peas and beans. ANASTOMOSIS (Gr. _aná_, through, and _stoma_, a mouth). The communication of vessels with each other, as of the arteries with the veins, which, by touching at numerous points, form a net-work or reticulation. See _Inosculation_. ANATOMY (Gr. _anatémnō_, to cut up). The science of organization; the science whose object is the examination of the organs or _instruments_ of life. Animal anatomy is divided into _human anatomy_ and _comparative anatomy_, according as it treats of the organization of the human body, or of that of other animals. AORTA (Gr. _aèr_, air, _teréō_, to keep; as having been formerly supposed to contain only air). The great artery of the heart. It is distinguished into the _ascending_ and _descending_. AQUEOUS. Watery. ARACANOID MEMBRANE (Gr. _arachnē_, a spider, and _eīdos_, likeness). The fine _cobweb-like_ membrane situated between the dura and pia mater. It is the serous membrane of the cerebro-spinal centers. ARBOR VITÆ. Literally, _tree of life_. A term applied to the arborescent appearance presented by the cerebellum, when cut into vertically. ARTERY (Gr. _aèr_, air, and _teréō_, to hold). A vessel which carries the blood from the heart; formerly supposed, from its being found empty after death, to contain only air. ARYTÆNOID (Gr. _arútaina_, a ewer, and _eīdos_, likeness). A term applied to two triangular cartilages of the larynx. AUDITORY (L. _audio_, to hear). Belonging to parts connected with the sense of hearing.