174 THE SHEPHEKD'S MANUAL. 



veins, the bones receive nutriment and means of growth or repair, 

 and by means of the nerves they become sensitive. 



The skeleton or frame work is clothed with flesh or muscular 

 tissue. The muscles consist of bundles of fibers which possess the 

 power of contraction when excited by sensations communicated 

 by the nerves. The muscles are very diversified in shape, some 

 being spread out in fan shape, some being thick and bulky, and 

 some long and thin. The fibers are intermingled with fat or with 

 cellular membrane. It is in the abundance of the cells which con- 

 tain the fat, and in the power to assimilate food to supply the fat, 

 that a sheep of a good breed or character is distinguished from one 

 of a poor or bad character. The abundance of fat cells both within 

 and upon the surface of the muscles gives the soft mellow hand- 

 ling which distinguishes an excellent mutton sheep. The muscles 

 are either directly connected by the ends of their fibers to the peri- 

 osteum or covering membrane of the bone, as in the scapula or 

 shoulder blade ; or the ends are gathered together closely and in- 

 terlaced with the stronger fibers of the tendons or ligaments which 

 are attached to the bones. By the contraction of the fibers of the 

 muscles and tendons, the movements of the joints are made. In 

 the muscular portions of the sheep consists the whole value of the 

 carcass to the butcher, and the whole art of the breeder and 

 feeder of those heavy-bodied breeds, known as mutton sheep, 

 is concentrated in the effort to increase the muscular development 

 in those parts of the carcass, as the loins and legs, the meat of 

 which is most highly valued. The muscles are enclosed hi the 

 skin which forms the covering of the animal. The protecting coat 

 of the animal grows upon the skin. This is either hair or wool, 

 both being of similar construction and composition, differing only 

 in form or degree of fineness and texture. 



The brain occupies the cavity of the skull, and is the central seat 

 of sensation and intelligence. From it proceeds the spinal marrow, 

 which is a continuation of the brain, and which occupies a cavity 

 through the center of the spine or backbone, from the head to the 

 tail. The brain is largely supplied with blood by means of the 

 carotid arteries, and the jugular veins serve to return the blood 

 from the brain to the heart and lungs. In the sheep the brain is 

 very small as compared with the size of the body, its average 

 weight being but 4 ounces, while that of the dog is 6| ounces. 

 This difference in the development of brain reasonably accounts 

 for the superior intelligence of the shepherd dog, one of which 

 easily controls and guides the movements of a thousand sheep. 



The nerves proceed from the brain and spinal cord, and pen) 



