5. The rhomboideus. Transect.
Recognize the levator scapulæ ventralis ([Fig. 68], f), the sternomastoid ([Fig. 68], c; [Fig. 65], g), and the cleidomastoid ([Fig. 65], h). Then dissect—
6. The levator scapulæ ventralis ([Fig. 68], f). Its origin ([Fig. 72], c, c′) cannot be seen at this stage and should be left until the cervical muscles are dissected. Be careful in transecting this muscle to separate it well from the cleidomastoid. Transect.
7. The cleidomastoid ([Fig. 65], h). Its origin cannot be fully seen at this stage. Transect.
Make a midventral incision of the skin from the cranial end of the manubrium to a point opposite the crest of the ilium. From the caudal end of this incision make an incision to the root of the tail. From the cranial end of the incision in the ventral middle line make a cut around the base of the fore limb on its caudal side, thus connecting the ventral incision with the incision which passes between the manubrium and the thirteenth thoracic vertebra.
Make another incision from the convexity of the knee at the joint along the fold of the skin which connects the hind limb and body, to the incision which leads to the root of the tail.
Reflect the flaps thus formed so as to expose the body and flank, removing the skin-muscle with the skin.
8. The latissimus dorsi ([p. 121], and [Fig. 68], m). Dissect it up and transect it. Work carefully toward its insertion and note the origin from its outer surface in the axilla of a part of the cutaneus maximus, and at about the same place of a thin muscle, the epitrochlearis ([p. 164], and [Fig. 65], r), without determining the insertion of the latissimus.
9. Dissect the pectoralis group of muscles ([Fig. 65], and [p. 144]), i.e., the pectoantibrachialis ([Fig. 65], m), the pectoralis major (l), pectoralis minor (o), and xiphihumeralis (p).
Determine the border of each muscle before lifting it, then work it up at its middle, transect it, and work toward its ends, determining origin and insertion.