



Dublin Microscopical Club. 2S3 



Bones. At first there was some difficulty in determining exactly 

 which bones appeared in the section ; but the following description 

 is correct. To the ulnar side lies the unciform, easily recognizable 

 by its hook-like process. Proceeding from it, the next bone in order 

 is the os magnum, then the trapezoid, and finally the trapezium. 

 The latter appears to have a division in it ; but this is not of any 

 importance. 



Tmdons. In the groove of the trapezium lies the tendon of the 

 flexor carpi radialis. At the most superficial part of the palmar 

 surface the tendon of the palmaris longus appears as a faint line. 

 In the centre lie the tendons of the flexors of the fingers. 



Annular ligament. The annular ligament can be seen stretching 

 from the hook-like process of the unciform to the trapezoid, and 

 sending a slip to the trapezium. 



Muscles. On the radial side the abductor pollicis, on the ulnar 





V 



* 



side the abductor minimi digiti. 



Vessels $c. Ulnar nerve and artery in the angle between the 

 annular ligament and the abductor minimi digiti. 



The second section, which passes through the bases of the meta- 

 carpal bones, shows : — 



Bones. The first and second metacarpals are narrower on the 

 palmar than on the dorsal aspect, the dorsal aspect of the latter 

 being rounded, whilst that of the former is angular. The third 

 roughly resembles one of the forms of shields on which coats of 

 arms are depicted. The fourth and fifth are approximately round. 



Muscles. In the thenar region, most externally the abductor pol- 

 licis, next to it the flexor brevis pollicis, then the opponens pollicis, 

 separated from the last by the tendon of the flexor pollicis longus, 

 and finally, deepest of all, the adductor pollicis. In the hypothenar 

 region, externally and quite distinct from the other muscles, there 

 is the abductor minimi digiti. Closer to the bone, on its ulnar 

 aspect, is the flexor brevis minimi, whilst on the palmar aspect a 

 few fibres represent the opponens minimi digiti. The line of de- 

 marcation between these last two muscles is difficult to make out. 

 * In the centre of the palmar aspect two lumbricales can be seen. 



In the third section, which passes through the centre or nearly 

 so of the metacarpal bones, attention is drawn to the following 

 points of interest : — 



Bones. The first metacarpal roughly resembles the figure conven- 

 tionally supposed to represent the heart, save that it is broader and 

 its apex (which is dorsally directed) blunter. The second and fourth 

 are nearly circular, and the third and fifth approximately oval. 

 By far the greatest distance between any of the bones is that which 

 intervenes between the first and second. The smallest is that be- 

 tween the second and third, whilst the distances between the third 

 and fourth and fourth and fifth are nearly equal. 



Muscles. The adductor pollicis, attached to the palmar and partly 

 to the ulnar aspect of the first metacarpal, can be seen extending 

 towards the centre of the palm. On the ulnar and solar aspect of 

 the fifth metacarpal there are two muscles, viz. nearest to the bone 



