These are so frequent that they can hardly be looked on as abnormal, but they must be accepted as pathological when they cause serious irritation or digestive disorder. This result is seen especially in the case of cutting or sharp pointed bodies, which beside wounding the walls of the rumen, show a marked tendency to advance to the heart and penetrate it, or to perforate the liver, diaphragm or abdominal walls and even to cause a fistula through which the ingesta escapes. _Causes._ The common cause in cattle is the habit of swallowing, after one or two strokes of the teeth, any small object that is mixed with the provender. Next to this comes the habit of stabled cows, and of such as suffer from a lack of phosphates or other important element in the food, of licking, chewing, and swallowing articles that can in no sense be considered as alimentary. Among the rounded or smooth bodies found in the rumen and reticulum may be named coins, rivets, fragments of wood, cords, pieces of rope, leather, gloves, cloth, small garments like vests or caps, ribbons, bones, pieces of lead, dried paints, cotton waste used as packing for machinery, shot, and even small animals such as frogs, toads, and snakes; also sand and pebbles. Among sharp or pointed bodies the most common are nails, pins, needles, baling wire, pieces of iron or other metals, knives, scissors, forks, fragments of glass, thorns, etc. _Lesions._ These are as varied as the nature of the traumatic agent, the seat and nature of the trauma. The rounded bodies, if non-poisonous, act merely by attrition of the walls and tend to induce a local catarrhal inflammation. Yet even sharp pointed bodies may prove comparatively harmless. The museum of the N. Y. S. V. College contains a pocket knife which had remained open in the rumen for a length of time without producing any visible injury.