CARPUS. 193 



rou<^h body is prominent forwards into the palm ; having the 

 tendon of the flexor carpi ulnaris, and a ligament from the 

 styloid process of the ulna fixed to its upper part ; the trans- 

 verse ligament of the wrist is connected to its external side : 

 li<raments extended to the unciforme bone, and to the os 

 metacarpi of the little finger, are attached to its lower part ; 

 the abductor minimi digiti has its origin from its forepart; 

 and, at the external side of it, a small depression is formed for 

 the psssage of the ulnar nerve. 



Second Row. 



Os Trapezium has four unequal sides and angles in its back 

 part, from which it has got its name. Above, its surface is 

 smooth, slightly hollowed, and semicircular, for its conjunction 

 with the OS scapholdes. Its internal side is an oblong concave 

 square, for receiving the following bone. The inferior surface 

 is formed into a pulley, which faces obliquely outwards and 

 downwards when the palm presents forward. On this pulley 

 the first bone of the thumb is moved. 



At the internal side of the pulley, a small oblong smooth 

 surface is formed by the os metacarpi indicis. The forepart 

 of the trapezium is prominent in the palm, and near to the in- 

 ternal side has a sinuosity in it, where the tendon of the flexor 

 carpi radialis is lodged, on the ligamentous sheath of which 

 the tendon of the flexor longus pollicis manus plays : near 

 this the bone is scabrous, where the transverse ligament of 

 the wrist is connected, the abductor and the flexor brevis 

 pollicis have their origin, and ligaments go out to the first of 

 the thumb. 



Os trapezoides, so called from the irregular quadrangular 

 figure of its back part, is the smallest bone of the wrist, except 

 the pisiforme. The figure of it is an irregular cube. It has a 

 small hollow surface above, by which it joins the scaphoides ; 

 a long convex one externally, where it is contiguous to the 

 trapezium ; a small internal concavity, for its conjunction 

 with the OS magnum ; and an inferior convex surface, the 

 edges of which are, however, so raised before and behind^, that 

 17 



