THE NECTURUS 25 



Cut through the coraco-braehialis and note the smaller 

 muscle beneath it. This is the coraco-braehialis brevis. 

 For* convenience, remove the girdle from the right side of 

 the animal and work out the rest of the muscles from the 

 detached limb. 



SCAPULO-HUMERALIS 



On the inner side of the girdle, note the small muscle that 

 originates from the posterior notch of the coracoid, and 

 from the posterior edge of the scapula. It extends to the 

 humerus where it is inserted on the inner face of the distal 

 end. To see the origin and insertion of this muscle, the 

 triceps should be dissected loose at the proximal end. 



MUSCLES OF THE CARPUS 



Study the muscles of the back of the hand, and separate 

 the three muscles that appear. The median muscle serves 

 as a landmark. 



Extensor metacarpals 



The origin is on the outer face of the distal end of the 

 humerus, and the insertion at the bases of the metacarpalia 

 where it ends in digitations. 



Extensor radialis 



This muscle is partially covered by the extensor meta- 

 carpalia. With this removed, the two slips of the ex- 

 tensor radialis are seen, an anterior and a posterior. The 

 anterior is the larger and longer. It originates on the outer 

 face of the condyle of the humerus and is inserted on the 

 outer face of the radius and on one of the carpal bones, 

 the radiale. 



The posterior slip is shorter. It originates posteriorly 

 to the other slip and is inserted on the radius. 



