11. There are several strong tendons to be seen and felt about the ankle. Behind is the _tendo Achillis_. It forms a high relief with a shallow depression on each side of it. Behind both the inner and outer ankle several tendons can be felt. Over the front of the ankle, when the muscles are in action, we can see and feel several tendons. They start up like cords when the action is resisted. They are kept in their proper relative position by strong pulleys formed by the annular ligament. Most of these tendons can be best seen by stand a model on one foot, _i.e._ in unstable equilibrium. III. Landmarks of the Heart. To have a general idea of the form and position of the _heart_, map its outline with colored pencils or crayon on the chest wall itself, or on some piece of clean, white cloth, tightly pinned over the clothing. A pattern of the heart may be cut out of pasteboard, painted red, or papered with red paper, and pinned in position outside the clothing. The apex of the heart is at a point about two inches below the left nipple and one inch to its sternal side. This point will be between the fifth and sixth ribs, and can generally be determined by feeling the apex beat. IV. Landmarks of a Few Arteries. The pulsation of the _temporal_ artery can be felt in front of the ear, between the zygoma and the ear. The _facial_ artery can be distinctly felt as it passes over the upper jaw at the front edge of the masseter muscle. The pulse of a sleeping child can often be counted at the anterior fontanelle by the eye alone. About one inch above the clavicle, near the outer border of the sterno-mastoid, we can feel the pulsation of the great _subclavian_ artery. At the back of the knee the _popliteal_ artery can be felt beating. The _dorsal_ artery of the foot can be felt beating on a line from the middle of the ankle to the interval between the first and second metatarsal bones. When the arm is raised to a right angle with the body, the _axillary_ artery can be plainly felt beating in the axilla. Extend the arm with palm upwards and the _brachial_ artery can be felt close to the inner side of the biceps. The position of the _radial_ artery is described in Experiment 102. Glossary. Abdomen (Lat. _abdo_, _abdere_, to conceal). The largest cavity of the body, containing the liver, stomach, intestines, and other organs. Abductor (Lat. _abduco_, to draw from). A muscle which draws a limb from the middle line of the body, or a finger or toe from the middle line of the foot or hand. Absorbents (Lat. _absorbere_, to suck up). The vessels which take part in the process of absorption. Absorption. The process of sucking up nutritive or waste matters by the blood-vessels or lymphatics. Accommodation of the Eye. The alteration in the shape of the crystalline lens, which accommodates, or adjusts, the eye for near or remote vision.