Wiist and Hand. 97 



line upwards on either side of the middle metacarpal bone y 

 crossing the line of the mid-carpal joint and terminating 

 above at the upper limit of the wrist joint. The two 

 spaces, external to the outer vertical line, correspond to the 

 trapezium with the trapezoid below, and to the scaphoid 

 above, while between the two vertical lines, the lower space 

 represents the os magnum, and the upper, the semilunar. 

 Internal to the inner vertical line, the space below, corre- 

 sponds to the unciform, while, that above, represents the 

 cuneiform and pisiform bones. (Fig. 5.) 



Lines for the Bloodvessels. The superficial palmar 

 arch may be represented by a line starting from the radial 

 side of the pisiform bone and running towards the cleft 

 between the metacarpal bones of the little and ring fin- 

 gers, then across the palnron a level with the junction of 

 the ulnar side of the thumb with the palm, when the for- 

 mer is at right angles to the latter. The digital branches 

 correspond to lines running down the interosseous spaces 

 and terminating about half an inch from the webs of the 

 ringers. 



The line for the radial artery is one starting below and 

 in front of the radial styloid process and terminating pos- 

 teriorily at the cleft between the metacarpal bones of the 

 thumb and index ringer, while in the palm, where it con- 

 stitutes the deep palmar arch, it is represented by a line 

 drawn from this cleft to the base of the little finger about 

 half an inch above the line of the superficial arch. Another 

 landmark for the deep palmar arch is : Place the thumb on 

 the front of the wrist between the pisiform internally, and 

 the scaphoid externally, so that the interphalangeal joint 

 will be opposite to the pisiform bone, then the tip of the 

 thumb will agree with the convexity of the arch. On the 

 dorsum of the hand the line for the radial has already 

 been described; that for the dorsalis indicis runs along 



