Percussion better than palpation enables one to delimit the space occupied by the liver, particularly towards the back, where there is no interposed layer of lung. Percussion is especially useful in detecting hypertrophy due to cancer, tuberculosis, echinococcosis of the liver, etc., or hepatic atrophy. In isolated cases icterus may exist, confirming the conclusions otherwise arrived at. =Pancreas.= The pancreas is situated rather deeply in the right sublumbar region, below the kidney, behind the liver, above the floating colon, and within the duodenal loop. It is therefore very difficult to examine; moreover, the diseases which affect it are still little understood. The point most prominently brought forward by this demonstration of the topographical anatomy and semiology of the digestive apparatus is the difficulty of accurately diagnosing digestive diseases in the ox when one confines oneself to a superficial examination. To have any chance of arriving at an exact diagnosis, methodical and thorough examination is indispensable. Given this condition, accurate diagnosis becomes possible, despite all difficulties. CHAPTER I. DISEASES OF THE MOUTH. STOMATITIS. =Definition.= By stomatitis we mean inflammation of the buccal mucous membrane. Stomatitis may be simple—_i.e._, due to accidental causes, to varying local forms of irritation, or to wounds; or, on the contrary, it may be specific, of infectious origin, like the stomatitis of foot-and-mouth disease, gangrenous coryza, cattle plague, etc.; or, finally, it may be of toxic origin, like the stomatitis of mercurial poisoning. Here we shall only study the simple forms of stomatitis, the gangrenous stomatitis of calves, and mercurial stomatitis. The others will be noticed in speaking of the diseases of which they form one of the symptoms. SIMPLE STOMATITIS. =Causation.= Simple stomatitis of bovine animals is often due to feeding with rough forage, or forage containing prickly or spiny plants, like thistles, sea holly, eryngo, etc. Sometimes it follows prolonged irritation by rough teeth, premolars or stumps, or accompanies the shedding of the temporary molars. Ingestion of irritant plants like nettles, certain specimens of the orders _Labiatæ_ and _Umbelliferæ_, leaves covered with vesicant insects, cabbage and turnip leaves infested with aphides, oil beetles, etc., or the swallowing of hot liquids, may also, though more rarely, produce it. Finally, in grave diseases of the digestive apparatus, the buccal mucous membrane may secondarily become affected.