ARLISS, GEORGE, an English actor, born in London in 1868. He was edu cated in that city and made his first appearance on the stage in 1887. In 1901 he toured America with Mrs. Pat rick Campbell, and in the following year played with Blanche Bates. He was later leading man for Mrs. Fiske. He made a great success in the title roles of " The Devil " and of "Disraeli." He was successful also in the play "Hamilton," 1917.
ARM, the upper limb in man, con nected with the thorax or chest by means of the scapula or shoulder-blade, and the clavicle or collar-bone. It consists of three bones, the arm-bone (humerus), and the two bones of the fore-arm (ra dius and ulna), and it is connected with the bones of the hand by the carpus or wrist. The head or upper end of the arm-bone fits into the hollow called the glenoid cavity of the scapula, so as to form a joint of the ball-and-socket kind, allowing great freedom of movement to the limb. The lower end of the humer us is broadened out by a projection on both the outer and inner sides (the outer and inner condyles), and has a pulley like surface for articulating with the fore-arm to form the elbow-joint. This
joint somewhat resembles a hinge, allow ing of movement only in one direction. The ulna is the inner of the two bones of the fore-arm. It is largest at the upper end, where it has two processes, the coronoid and the olecranon, with a deep groove between to receive the hu merus. The radius—the outer of the two bones—is small at the upper and expanded at the lower end, where it forms part of the wrist-joint. The mus cles of the upper arm are either flexors or extensors, the former serving to bend the arm, the latter to straighten it by means of the elbow-joint. The main flex or is the biceps, the large muscle which may be seen standing out in front of the arm when a weight is raised. The chief opposing muscle of the biceps is the tri ceps. The muscles of the fore-arm are, besides flexors and extensors, pronators and supinators, the former turning the hand palm downward, the latter turning it upward. The same fundamental plan of structure exists in the limbs of all ver tebrate animals.