The =suspensory= ligament of the liver passes from the caudal surface of the diaphragm and the median ventral line for about one or two centimeters caudad of the diaphragm, to the liver, and extends between its two halves. The =ligamentum teres= or round ligament is the thickened free caudal border of the suspensory ligament. It is the remains of the fœtal umbilical vein. From the dorsal border of the liver the peritoneum which covers its cranial surface turns ventrad onto the caudal surface of the diaphragm, while that which covers its caudal surface turns dorsad onto the caudal surface of the diaphragm to reach the dorsal body wall. Between these two sheets a small linear part of the surface of the liver is closely applied to the diaphragm without intervening peritoneum. The two sheets which bound this area constitute the =coronary= ligament of the liver. This ligament is broader where it passes from the left lateral lobe to the diaphragm and is called the =triangular= ligament. (There is perhaps a corresponding right triangular ligament, from the cranial division of the right lateral lobe.) The caudal division of the right lateral lobe is held to the kidney of that side by the =hepatorenal= ligament. II. THE ALIMENTARY CANAL. APPARATUS DIGESTORIUS. The alimentary canal may be divided into mouth, pharynx, œsophagus, stomach, small intestine, and large intestine. With these are associated certain accessory structures,--the salivary glands, the liver, and the pancreas. The spleen, though not belonging to the digestive system, is usually described in connection with it. The respiratory organs are almost throughout in close relation with the organs of the digestive system. 1. =The Mouth. Cavum oris.=--The mouth cavity extends from the lips to the pharynx. It is narrower toward the lips, broadens caudad as far back as the last teeth, then becomes narrowed to form the =isthmus faucium=, by which it communicates with the pharynx. The mouth cavity is divisible into the =vestibule= of the mouth (=vestibulum oris=), which comprises that part outside the jaws proper, bounded externally by the lips and cheeks, and the =mouth cavity proper= (=cavum oris proprium=), which lies within the teeth. That portion of the vestibule which is bounded by the cheeks is sometimes farther distinguished as the =buccal cavity=. The entire mouth cavity (except the teeth) is lined by the mucous membrane or =mucosa=.