STRUCTURE OF THE SHEEP. 293 



united with the granular is exhibited in the texture of the 

 glands, and in the medullary substance of the nervous sys- 

 tem ; and the globular is shown in the composition of the 

 chyle, the blood, and several of the secretions. These sev- 

 eral textures being combined together in different propor- 

 tions, we have the various organs of which the body is com- 

 posed. 



To give support to the animal frame, and afford fixed objects 

 for the attachment of various parts, is the use of the skeleton, 

 which is composed in the sheep of nearly two hundred bones 

 of various sizes and shapes. These bones, in order to admit 

 of motion, are connected one to another by means of strong 

 bands called ligaments, the ends of the bones being con- 

 structed in various ways so as to admit of motion ; in many 

 we have the form of a hinge, in others that of a ball and 

 socket. The motion of the limbs is effected by means of 

 the muscles or flesh, which, although to a casual observer 

 appearing as a homogeneous mass, is readily separable into 

 a greater number of distinct bodies of various forms and sizes. 

 These muscles have commonly two separate attachments, 

 which are usually bones, and by contracting in length, they 

 bring these points of attachment nearer to each other. Mus- 

 cles are composed of a vast number of fibres, which, on 

 being acted on by nervous influence, diminish in length and 

 increase in bulk, and thereby approximate the different ob- 

 jects to which they are attached. They are usually fastened 

 to bones by means of a strong white substance called tendon, 

 which, however, possesses in itself no power of contraction, 

 but merely communicates the contractile force to the object 

 to be acted on. Where the two objects of attachment are 

 distant from each other, the greater portion of the distance 

 is occupied by the tendons, the advantage of which is owing 

 to their diminished size in proportion to their strength ; thus 

 we find the legs of sheep below the knee are light and slen- 

 der, from the absence of muscular and the substitution of 

 tendinous substance. The greater part of the muscles are 

 voluntary, being under the control of the mind ; but some 

 are involuntary, such as the heart and the diaphragm. 



Muscles are extensively supplied with vessels of various 

 kinds, such as arteries for their nourishment, and veins for 

 the return of the blood after this purpose is effected. They 

 have likewise nerves, which not only furnish sensation, but 

 also communicate to them the mandates of the will. 

 2.5* 



