The stomach lies at the cranial end of the abdominal cavity, mostly to the left of the middle line. Its cardiac end is in contact by its dorsal surface with the dorsal, nearly horizontal, portion of the diaphragm. On its ventral side the cardiac end does not touch the diaphragm, so that a small part of the œsophagus passes here for a short distance into the abdominal cavity, to join the stomach. The communication of œsophagus and stomach is by a simple conical increase in size of the former. The pyloric end of the stomach extends to the right of the middle line, becoming constantly smaller; at its junction with the duodenum there is a constriction which marks the position of the =pyloric valve= (_f_). This valve is formed by a ring-like thickening of the circular muscle-fibres of the alimentary canal, forming a sphincter muscle at the junction of the stomach and duodenum and causing a projection of the mucosa into the lumen of the canal. The ventral surface of the stomach lies against the liver except when the stomach is much distended with food, when the ventral surface comes to lie against the ventral abdominal wall. [Illustration: FIG. 97.--STOMACH, VENTRAL VIEW. _a_, œsophagus; _b_, cardiac end of the stomach; _c_, lesser curvature; _d_, greater curvature; _e_, fundus; _f_, pyloric valve; _g_, part of duodenum.] The stomach is supported by the =great omentum= and the =gastrohepatic= ligament. It is connected with the duodenum by the =gastroduodenal= ligament; with the spleen by the =gastrolienal= ligament. The inner surface of the stomach presents longitudinal folds at its pyloric end and along the greater curvature as far as the fundus. The prominence of these depends on the degree of distension. Its walls are composed of an external peritoneal layer, an internal mucous layer, and an intervening muscular layer. This may be seen with the unaided eye in sections of the wall. 5. =The Small Intestine. Intestinum tenue.=--The small intestine lies in numerous coils which take up the greater part of the space in the abdominal cavity. It has a length about three times that of the body of the cat. It is usually considered as divided into three parts, =duodenum=, =jejunum=, and =ileum=; these divisions are, however, not clearly marked off. The small intestine is suspended by the =mesentery= already described.