Chap.xv.i THE WRIST AND HAND. 265 



"tabatiere." On the back of the hand the various 

 tendons and the surface veins can all be well made 

 out. Between the first and second metacarpal bones 

 is the first dorsal interosseous muscle, which forms a 

 conspicuous prominence when the thumb is pressed 

 against the side of the index finger. The three rows 

 of knuckles are formed by the proximal bones of the 

 several joints. 



The wrist and hand. The skin of the palm 

 and of the front of the fingers is thick and dense, 

 while that on the back of the hand is much finer. 

 The palm, the fronts, and sides of the fingers, and the 

 dorsal aspects of the last phalanges, all show an entire 

 absence of hair, and of sebaceous glands. These parts 

 are, therefore, exempt from the maladies that attack 

 hair follicles and their gland appendages. On the 

 dorsum of the hand, and of the first and second rows 

 of phalanges, there are numerous hail's and sebaceous 

 follicles. Sweat glands are more numerous in the 

 skin of the palm than in any other part. According 

 to Sappey they are four times more numerous here than 

 they are elsewhere. Krause has estimated that nearly 

 2,800 of these glands open upon a square inch of the 

 palm. Only about half the number are found upon 

 the dorsum of the hand. The profuseness with which 

 the palm may perspire is well known, and is very 

 marked in certain conditions. The cutaneous nerve- 

 supply of the hand is very free. The nerves present 

 Pacinian bodies, which are far more numerous in the 

 hand than in any other part, and in no portion of 

 the surface are tactile corpuscles more numerous or 

 more highly developed. With the exception of the 

 tip of the tongue, a more acute degree of tactile 

 sensibility is met with in the hand than in any 

 other part. The most sensitive district is the 

 palmar surface of the third phalanx of the 

 index finger, while the least sensitive to tactile 



