450 APPENDIX. 



upon the front of the carpus. This ribbon divides into three portions ; 

 the small internal one, passing down to the inner edge of the foot, 

 divides into two slips, one for the fourth, the other for the fifth 

 digits ; it is connected by a transverse slip to the middle division ; 

 the middle division reunites along the metatarsal region with the 

 external division ; they separate again at the base of the first pha- 

 langes — the middle division passing on to the third toe, the external 

 division dividing between the first and second toes. 



Extensor primi et secundi digitorum arises from the arti- 

 cular surface of the ulna over a narrow space or line about its 

 middle, and, under cover of the common extensor, comes out from 

 beneath it, and is tied down by the annular ligament near the trans- 

 verse ligament on its outer side ; continuing fleshy beyond the liga- 

 ment, terminates in a small tendon, which, splitting at its extremity, 

 is attached to the phalanges of the first and second toes. 



Extensor ossis metaearpi pollicis. — A fleshy mass arising from 

 the anterior surface of the ulna along with the last muscle, but 

 principally from the front of the radius. From its head down- 

 wards to its lower fifth its fibres are oblique, terminate, in a strong 

 tendon on its outer edge, and continue with the tendon down to 

 the annular ligament, by which it is tied down in the hollow on 

 the outer edge and back part of the radius. Its tendon, thick like 

 a rope above, flattens out below, doubles upon itself, so as to form 

 two lamina?, which are inserted continuously to the metacarpal bone 

 of the first toe. 



Extensor carpi radialis longus arises from the humerus by 

 a small origin in front, and to the outer side of the rough im- 

 pression of the centre of its anterior ridge. This is a comparatively 

 small elongated muscle, intimately attached about its middle to the 

 thick portion of the aponeurosis of the arm, to which the cervico- 

 humeral muscle is attached. The muscle itself forms the anterior 

 margin of the anterior muscular prominence between the upper arm 

 and forearm, and, extending downwards, terminates in a rope-like 

 tendon, which is crossed obliquely by the tendon of the extensor 

 ossis metaearpi pollicis, and is tied down in a sheath formed by 

 the annular ligament in a groove on the fore-part of the outer sur- 

 face of the radius, and is inserted into the front of the scaphoid 

 bone. 



