92 ELEMENTS OF MAMMALIAN ANATOM\ 



thus leaving to the student the pleasure of working out the 

 details. In general, the arrangement and descriptions follow 

 Reighard and Jennings very closely, however, in nearly every 

 case they have been verified by special dissections and in class 

 work. The student will be interested in finding many minor 

 variations which will add zest to the work. He should also note 

 carefully the muscles which together effect a certain motion, 

 such as the flexion of the forearm or the extension of the digits. 



DESCRIPTION OF MUSCLES 



The skin muscles are usually removed with the skin and are 

 rather difficult to study. 



(i) Cutaneous maximus has its origin from the outer surface 

 of the latissimus dorsi; the bicipital arch in the axilla; the linea 

 alba and from the thorax; and is inserted onto the skin. It 

 covers almost the whole side and moves the skin. 



(2) Platisma: from the middorsal line from occiput to first 

 thoracic vertebra, and from side of neck; to the skin and muscles 

 of face and neck. A thin muscle covering side of face and neck 

 and sometimes described as two muscles, the portion dorsal 

 to insertion in skin is known as the supercervicocutaneous and 

 the portion ventral to the insertion as the cervicofacial muscle. 



MUSCLES OF THE SHOULDER REGION 



These muscles of the forelimb (3-45) will usually be dissected 

 in a short course. The more difficult muscles of the hand may be 

 omitted except for students who have developed a careful tech- 

 nique. Drawings should be made during the progress of 

 dissection. The exact determination of origin and insertion 

 should be deferred until later in any case where it would injure 

 undissected parts. 



(3) Spinotrapezius (Fig. 54) (Trapezius inferior); neural 

 spines of thoracic vertebra} to spine of scapula and adjacent 

 fascia; draws scapula upward and backward. 



