24 INTRODUCTION. 



a reservoir of nutritive matter for the support of the animal under any 

 accidental want of nourishment. 



Connected with the fat is the cellular membrane, formed likewise 

 of membranous cells, but which communicate with each other through 

 the whole of the body. There is sufficient but disgusting proof of 

 this in the blowing up of the calf just killed. The crackling heard 

 when the skin of cattle labouring under inflammatory fever is pressed 

 upon, is another proof, for the gas which was produced by the com- 

 mencement of putrefaction is forced into the neighbouring cells. 



The cellular membrane is the connecting medium between almost 

 all the component parts of the frame. 



The Muscles. — The muscles are accumulations of fibres or cords, 

 running parallel to each other, and bound together by cellular mem- 

 brane, and by the tiohtening or contraction of which the various parts 

 of the body are moved. They arise from some fixed point, and are 

 inserted either by a diminution of their substance, or in the form of a 

 tendon, into a bone or part that is movable. Nervous fibrils are sent 

 to all these muscles from the spinal cord, by the influence of which 

 they contract or shorten, and the bone or movable part into which the 

 tendon is inserted is acted upon ; and if both the parts from which 

 they arise, and into which they are inserted, are movable, both change 

 their place. 



There are other muscles, as those of the heart and the intestines, 

 which are moved by nervous influence not arising from the spinal 

 cord and the brain, and not under the influence of the will. It is 

 proper that the powers of circulation and digestion should be perfectly 

 independent of the will. The sources whence these powers are de- 

 lived will be presently spoken of. 



The Brain. — The brain is a pulpy substance contained in the cavity 

 of the skull. By means of the spinal cord (which is a continuation 

 of its substance), and the nerves which proceed from the spinal cord, 

 it holds correspondence with the whole frame, imparting sensibility 

 everywhere, and giving motion to every part that is capable of volun- 

 tary action. 



The five senses, viz., vision, hearing, feeling, tasting, and smelling, 

 so necessary to the animal's existence and well-being, are all situated 

 in the head, and not far distant from the brain. The organs of these 

 senses are the eyes, ears, lips, tongue, and the internal parts of the 

 nose. These have nerves sent to them from the brain, by v.'hich the 

 impressions made upon them by external objects are immediately 

 communicated to that important organ, and the animal is rendered 

 conscious of surrounding objects, and their forms and qualities. 



Nine pairs of nerves arise from the base of the brain, and proceed, 

 through holes in the skull, to the face and head principally; but some 

 of them wander farther, for the purposes of feeling and motion. The 

 Jirsl pair are the nerves of smelling; they pursue a short course to 

 the nose. The second pair go to the eyes, and are the nerves of vision : 

 the third and fourth pairs are distributed to the muscles that move 



