48 ANATOMY OF THE RABBIT 



divided, by the interscapular aponeurosis, into cranial, (la) and 

 caudal portions (ib) which are separated between the scapulae 

 by a ghstening, wide, thin, tendonous membrane, the inter- 

 scapular aponeurosis. The trapezius is very thin and wide, 

 consequently it is very easily, mutilated. 



la. Anterior trapezius (acromio-, superior trapezius) m: 

 Occipital bone, vertebral spines and dorsal ligament of neck and 

 interscapular aponeurosis. Draws glenoid end of scapula 

 dorsocraniad. Method: Clear all fat and fascia off the side of 

 the neck so that the space between the ventral border of the 

 anterior trapezius m. and the dorsal border of the levator 

 scapulae ventralis m. (3) will be plainly visible, about midway 

 between the shoulder joint and the base of the ear. This inter- 

 muscular space is usually filled with fat and consequently 

 readily located. Begin at this point to probe under the muscle 

 with the grooved director. After ha\dng explored this region, 

 by probing, force the point of the grooved director through the 

 fascia at a point midway between the first long neural spine 

 (second thoracic) and the superior angle of the scapula, as shown 

 in figure 18. With the point of the scissors gliding along in the 

 groove of the director transect this muscle through its middle 

 and complete the dissection, but do not try to separate the two 

 trapezius muscles from each other. 



lb. Posterior trapezius (spino-, inferior trapezius) m: 

 Spinous processes of last six to ten thoracic vertebrae and 

 lumbodorsal fascia; to dorsal half of spine of scapula. Draws 

 scapula dorsocaudad. Method: Begin probing by inserting 

 the grooved director under the cranial margin of this muscle at 

 the point where the transection of the anterior trapezius m. 

 ended. The ventral margin of the belly of this muscle is more 

 or less fused with the belly of the latissimus dorsi m. (2) . Using 

 the grooved director and scissors transect this muscle from the 

 point of entrance between the scapulae ventrocaudad and com- 

 plete the dissection. Do not attempt to separate the proximal 

 half from the latissimus dorsi, but the distal half must be sepa- 

 rated from the latissimus dorsi muscle. 



