THE MUSCLES. 95 



or part to which they are attached. Thus the sterno- 

 mastoid muscle arises on the sternum and is inserted on 

 the mastoid process of the skull. The latissimus dorsi is 

 so named because it is a very broad muscle (Fig. 47) 

 and occupies the dorsal part of the cat's body. The 

 extensor communis digitorum muscle signifies by its 

 name that it is the common extensor of the digits. 



DISSECTION OF THE MUSCLES. 



Since the other systems are of more importance from 

 the standpoint of comparative anatomy and physiology 

 than the muscular, only the more important muscles will 

 be described. Great care should be exercised in removing 

 the skin of the cat, in order that such superficial muscles 

 as the platysma myoides on the neck and side of the 

 face, and occipitofrontalis, may not be cut away. The 

 skin is attached to the underlying muscles by the super- 

 ficial fascia, a fibrous areolar tissue, which contains the 

 subcutaneous fat more or less abundant in all specimens. 

 The deep fascia is the fibrous and membranous layer 

 of dense tissue lying close against the muscles and dipping 

 down between them. The stronger parts of this fascia 

 are called aponeuroses. 



Directions for Dissection.- -Dissection does not mean 

 the cutting up, but the intelligent separation of one 

 organ from another without removing the same. The 

 muscles should not be cut loose from their origin or 

 insertion, but merely separated from each other by cut- 

 ting the deep fascia in the longitudinal direction of the 

 muscle. If it is necessary to remove a muscle for dis- 

 playing those beneath, it should be cut transversely in 

 the middle and the two parts reflected. No portion of a 

 muscle or other tissue should be removed without know- 



