_Symptoms._ Generally these balls cause no appreciable disturbance of the functions of the stomach. This is especially true of the large, old and smoothly encrusted masses. The museum of the N. Y. S. V. College contains specimens of 5½ inches in diameter, found after death in a fat heifer, which had always had good health and which was killed for beef. This is the usual history of such formations, they are not suspected during life, and are only found accidentally when the rumen is opened in the abattoir. The smaller specimens, the size of a hen’s or goose’s egg, or a billiard ball, have produced severe suffering, with gulping, eructation, vomiting and tympany from obstruction of the demicanal or gullet, and such symptoms continued until the offending agents were rejected by the mouth. (Caillau, Leblanc, Prevost, Giron). Again they may block the passage from the first to the third stomach (Schauber, Feldamann, Adamovicz, Tyvaert, Mathieu). In calves on milk they are especially injurious as beside the dangers of blocking the passages already referred to, the unencrusted hairs and straws irritate the mucous membranes and still worse, the putrid fermentations going on in their interstices, produce irritant and poisonous products, and disseminate the germs of similar fermentations in the fourth stomach and intestine. Here the symptoms are bloating, colics, impaired or irregular appetite, fœtid diarrhœa, fœtor of the breath and cutaneous exhalations, and rapidly progressive emaciation. _Diagnosis_ is too often impossible. Tympanies, diarrhœa, colics, etc., may lead to suspicion, but unless specimens of the smaller hair balls are rejected by the mouth or anus there can be no certainty of their presence. If arrested in the cervical portion of the gullet they may be pressed upward into the mouth by manipulations applied from without. The looped wire extractor may be used on any portion of the œsophagus. If lodged in the demicanal the passage of a probang will give prompt relief. If retained in the rumen and manifestly hurtful, rumenotomy is called for as soon as a diagnosis can be made. FOREIGN BODIES IN THE RUMEN AND RETICULUM. Common. Harmless or injurious. Perforating objects. Traumatisms of contiguous organs. Causes; hurried primary mastication, morbid appetite. Bodies found. Lesions; catarrh, perforations, congestions, ulcerations of mucosa, abscess, trauma of liver, spleen, diaphragm, abdominal and thoracic walls, lung, pleura, pericardium, heart. Symptoms; absent, or, indigestion, tympany, eructations, hepatic, respiratory or circulatory disorder, colics, local tenderness, crepitation, substernal exudate, costiveness, difficult urination or defecation, bloody fæces, nervous disorder. Treatment; Prevention; avoidance of causes, gravitation methods, incision.