246 MANUAL OF MODERN FARRIERY 



digestion, and where it may be said properly to 

 commence. This is called the gastric juice, which 

 mixes with the food already softened, and converts it 

 into that fluid substance called chyme. 



, c. The margin which separates the cuticular from the villous 

 portions. 



d. The entrance from the gullet into the stomach. The 

 circular layers of muscles which invest this part are 

 very strong and thick. By their powerful contractions 

 they assist in rendering it difficult for the food to be 

 returned or even vomited. This orifice is called the 

 cardiac orifice, in consequence of its contiguity to the 

 heart. It is constantly closed by strong muscular fibres, 

 except when the food is passing through it into the 

 stomach. 



f. The oesophagus, or gullet, through which the food is 



conducted from the pharynx into the stomach. It has 

 its commencement in the pharynx, and is there placed 

 at the upper and back part of the larynx, the first part 

 of its course being behind the trachea, between it and 

 the cervical vertebrae. After proceeding a short way 

 down, it inclines to the left, and soon after makes its 

 appearance altogether on the left side of the trachea, 

 and continues so on its passage down the neck. This 

 will explain what has puzzled many, why we look for 

 the bolus during the act of swallowing on the left, and 

 not on the right side of the animal. Accompanying 

 the trachea, the oesophagus enters the chest between 

 the first two ribs, at which part, running above that 

 tube, it diverges from the trachea, and in connection 

 with the superior mediastinum, and traversing that 

 cavity a little way below and to the right of the 

 aorta. 



g. The communication between the stomach and the first 



intestine. 



i. A small orifice through which a portion of the secretion 

 of the pancreas enters the intestines. Its direction will 

 be seen by the probe which is passed through it. The 

 pancreas, otherwise called the sweetbread, is a glandular 

 body lying across the spine in the epigastric region, 

 underneath the crura of the diaphragm, immediately 



