264 SURGICAL APPLIED ANATOMY. [Chap. xv. 



little finger, and double for the other two. It is 

 placed neaiiy three-quarters of an inch below the 

 corresponding joint. The middle folds are double for 

 all the fingers, and are exactly opposite the first inter- 

 phalangeal joints. The lowest creases are single, and 

 are placed a little above the corresponding joints (I to 

 2 mm., according to Paulet). There are two single 

 creases 011 the thumb corresponding to the two joints, 

 the higher crossing the metacarpo-phalangeal articula- 

 tion obliquely. The free edge of the web of the fingers, 

 as measured from the palmar surface, is about three- 

 quarters of an inch from the metacarpo-phalangeal 

 joints. The superficial palmar arch may be repre- 

 sented by a curved line across the palm starting from 

 the pisiform bone and running in a line with the 

 palmar border of the thumb when outstretched at 

 right angles with the index finger. The deep arch is 

 between a quarter and half an inch nearer the wrist. 

 The digital arteries bifurcate about half an inch above 

 the clefts between the fingers. 



The dorsal surface of hand. On the outer side 

 of the wrist, when the thumb is extended, a hollow is 

 obvious between the extensores ossis metacarpi and 

 forevis pollicis and the extensor longus pollicis. 

 French writers have termed this hollow "tabatiere 

 anatomique." Across this hollow and beneath the 

 tendons just named runs the radial artery. Under the 

 skin over the space can usually be seen a large vein, 

 the cephalic vein of the thumb/. Across the space 

 also runs the internal division of the terminal branch 

 of the radial nerve. In the floor of the " snuff- 

 box " are the scaphoid bone and the trapezium. The 

 extensor longus pollicis crosses the apex of the 

 first interosseous space. The sesamoid bones of 

 the thumb and the joint between the trapezium 

 and the first metacarpal bone can be well made out. 

 The latter articulation is situate on the floor of the 



