THE ANATOMY OF THE HORSE. 35 



called the peritoneum which wnen inflamed is called peritonitis, 

 a very dangerous disease, more so than pleurisy. 



PROCESS OF DIGESTION. 



In tracing- the food from the mouth to where it nourishes the 

 muscles in different parts of the body, we first find the food taken 

 into the mouth by the use of the lips and front teeth w^here it is 

 masticated or chewed by means of the tongue and teeth, and while 

 it is being rolled around and chewed the salivary glands keep 

 pouring in the saliva, mixing the food and preparing it for 

 digestion. After it is thoroughly chewed it is rolled into a ball at 

 the back part of the tongue, where by the action of the muscles of 

 the gullet it is grasped and forced down into the tube which, by 

 the action of its muscular fibres, is forced down into the stomach 

 where it is rolled about and becomes thoroughly mixed with the 

 gastric and pepsine juices which act chemically on the food and 

 changes it into what is known as chyme. From the stomach it 

 passes up into the front part of the small bowels where there is the 

 secretion from the liver and pancreas which also act chemically and 

 changes the chyme into what is called chyle. After this the rest 

 of the bowels, by the action of these little villi and lacteals, which 

 are in the coats of the bowels, absorbs the chyle or nourishment 

 from the food, these vessels empty the chyle or nourishment into 

 the veins of the body which is then carried to the heart, where it 

 is forced out from the heart through the arteries down into the 

 capillaries which are all through the body, the nourishment is 

 given through the walls of thes3 small thin vessels and gives life 

 and strength to the body. 



CHAPTER VIII. 



ORGANS OF RESPIRATION. 



THESE are commonally known as the organs of breathing, 

 they comprise the nostrils, chambers in the head or nasal 

 chambers, larynx or sometimes called Adam's apple, 

 trachea or windpipe, bronchial tubes and the lungs. 



The Nostrils are two openings, one on each side of the nose; 

 these are held open by the aid of cartilage or gristle, and muscles. 

 -About one and one-half inches up the nostril on the under side is a 

 small opening about the size of a grain of shot, this is where the tube 

 •or duct which carries the tears down from the eyes empty into the 

 nose. The nostril is lined with a thin delicate skin which after- 



