110 ANATOMICAL STEUCTUEE OF THE SHEEP. 



Vht Muscular System. 



Muscles are fibrous organs, possessing the property of con- 

 traction under the influence of a stimulus. While the shape of 

 the body depends to a great extent on the bony framework, there 

 is a vast difference between the appearance of the skeleton and 

 the body itself. 



The muscles are the flesh of the animal, attached to and 

 -covering every part of the skeleton. 



The motion of any and all parts of the body is dependant on 

 the contraction of the muscles attached to those parts. Muscles 

 are attached to different bones. Their contraction drawing the 

 parts together causes motion, thus limbs are bent, the head raised 

 and lowered, and the slightest movement even of an eyelash 

 controlled. 



Those which bend or flex the limbs are called flexor muscles, 

 those extending the same being called extensor muscles 



Muscles vary in size from the lai'ge muscles of the loin and 

 shoulder to those almost microscopical in size of the internal ear. 

 Some are thick and bulky, others extremely short, others cylin- 

 drical and of great length. Muscles are supplied with nerves, 

 blood vessels and absorbents. The nerves in muscle tissue are 

 those of motion and sensation ; those of motion convey the man- 

 dates of the will, thus causing motion; those of sensation com- 

 municate the sense of feeling, being the medium both of jiain 

 and pleasure. Muscles are composed of bundles of muscle fibres, 

 bound together by a cellular membrane. In sheep we find they 

 are for the most part clothed in fat, and also that fat is deposited 

 among the fibres. It is the ability of the animal to contain this 

 fat and the abundancy of the adipose membrane surrounding it, 

 which distinguishes a good sheep from one of an inferior breed, 

 giving to the former the soft and elastic feel to the hand, even 

 when the animal is in poor flesh. 



