PRACTICAL DIRECTIONS. 437 



necting 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 inser- 

 tion 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 (/), 

 pectoralis minor (0), 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, determin- 

 ing origin and insertion. 



Refer constantly to the skeleton. 



10. Then recognize the teres major (p. 163, and Fig. 75, d; Fig. 

 77, c) and the common insertion of the teres major and latissimus 

 (Fig. 79, d'); find the bicipital arch (Fig. 65, /') and determine its 

 composition (p. 166). 



n and 12. The serratus anterior and levator scapulae (Fig. 73, 

 h and t, and p. 122). In order to expose the origin of these muscles, 

 the external oblique muscle (Fig. 68, p] must be recognized, and that 

 part of it which has its origin from the fourth to the ninth rib should 

 be transected about an inch and a half from its origin and reflected. 



The thoracic portion of the rectus abdominis (Fig. 73, k) and of 

 the scalenus (Fig. 73, f-f") should also be recognized and then 

 raised at their outer borders and displaced toward the median line. 

 No part of any of these muscles should be removed or cut except as 

 directed. 



The serratus anterior and levator scapulae should be transected 

 and reflected to get at their origin and insertion. 



B. Muscles of the Arm (p. 156). The arm is thus removed from 

 the body and the dissection may be continued on the separated arm. 



13. The clavobrachial (Fig. 65, k, and p. 157). Its origin is best 

 seen later. Dissect it up, but do not transect it. 



Search now with great care for the coracobrachialis. Consult the 

 figures (Fig. 79, c) and descriptions (p. 164), and be especially care- 

 ful not to injure the long head of the muscle and its tendon. 



14. Dissect the coracobrachialis (Fig. 77, _/"). Cut and reflect it. 



15. The subscapularis (Fig. 77, a, and p. 161). Near its glenoid 

 end, its glenoid and coracoid borders are separated by triangular 

 intervals from the adjacent muscles. Transect the muscle by a line 

 connecting the apices of these triangles. Carry an incision from the 



