THE ANATOMY OF THE HOKSE. 21 



head to supply the different organs situated there, such as the 

 optic nerve, which passes down to the eye, giving the sense ot 

 sight. The auditory nerve passes down to the drum of the 

 ear to give the sense of hearing. The aulfactory nerves, which' 

 give the sense of smell, are situated in the mucus membrane 

 lining the nose. The nerves passing down to the tongue give 

 the sense of taste. Other nerves pass down to the lips, teeth, 

 mouth and face, giving motion and feeling to the parts mentioned ; 

 others pass down to the gullet or pharynx, giving it the power of 

 swallowing. In passing from the brain along the spinal cord, 

 which is situated in the opening of the bones of the back, there 

 are numerous small nerves given off to supply the muscles of 

 the neck, giving the neck motion and feeling. About opposite the 

 shoulder blade, or withers, the spinal cord gives off a large bunch 

 of nerves, part of which supplies the heart and lungs with nervous 

 power. This is a point of importance, for if the spinal cord 

 becomes injured in front of these nerves it causes immediate death. 

 The other part of this bunch of nerves supply the shoulder, chest, 

 and muscles of the front legs. Passing backwards along the 

 spinal cord is found the sympathetic system of nerves, which go 

 to supply the bowels, stomach, liver, kidneys, and other organs 

 situated in the abdominal cavity. Continuing backwards along 

 the spinal cord, to about opposite the hip bones, we find another 

 lot of nerves, one of which goes to supply the rectum, or back 

 bowel ; this gives the power of passing manure. Others go to 



* 



the womb and bladder ; these assist in urinating by con- 

 tracting the bladder. Other nerves pass to the small organs 

 situated in the pelvic cavity; some of these nerves pass dow'i to the 

 hind legs, supplying them with nervous power. The balance of 

 the nerves of the spinal cord go to supply the tail. 



Nerves have the appearance of bunches of white thread held 

 together by connective tissue. 



