=The Hand.=--The hand contains nineteen bones, five _metacarpal bones_, one for each finger and the thumb, whose bases articulate with the lower row of wrist bones, and fourteen _phalanges_, three for each finger and two for the thumb, of which the first row articulate with the metacarpal bones. They are all long bones and are slightly concave anteriorly. When the hand is flexed it is the heads of the metacarpal bones, not the bases of the phalanges, that are so prominent, the head of the third metacarpal being most prominent. The metacarpals are seldom _fractured_, though bad fractures occasionally occur. In comminuted fracture nothing can be done but remove the bone. If the periosteum is left the bone will grow again. Two diseases sometimes affect the metacarpals and the phalanges, _tuberculosis_ and _syphilis_. Both cause swelling of the bones. =Muscles of the Forearm.=--The chief groups of muscles on the forearm are the _flexors_ and _pronators_ on the anterior surface and the _extensors_ and _supinators_ on the posterior surface. In general the flexors and pronators take their origin from on or around the internal condyle, while the extensors and supinators arise on or around the external condyle. Where not otherwise stated it will be understood that such is their origin. In a general way they may by grouped as follows: ANTERIOR SURFACE. { flexor carpi radialis Flexors of wrist { flexor carpi ulnaris { palmaris longus Flexors of fingers { flexor sublimis digitorum { flexor profundus digitorum Flexor of thumb flexor longus pollicis Pronators of hand { pronator radii teres { pronator quadratus POSTERIOR SURFACE. Extensor of forearm anconeus { extensor carpi radialis longior Extensors of wrist { extensor carpi radialis brevior { extensor carpi ulnaris { extensor ossis metacarpi pollicis Extensors of thumb { extensor primi internodii pollicis { extensor secundi internodii pollicis Extensor of fingers extensor communis digitorum Extensor of index finger extensor indicis Extensor of little finger extensor minimi digiti Supinators of hand { supinator longus { supinator brevis