_Causes._ A predisposition to the affection occurs in the weak and debilitated, the overworked oxen, underfed cattle, in those that are just recovering from a severe illness and in which the gastric secretions and functions are still poor. The usual exciting cause is some fault in the food, it may be a sudden change from one kind to another, and especially from dry to green, or from one kind of green food to another and more tempting one, as when the animal breaks into a field of grain which is advancing to maturity. Even a sudden change of water, as from soft to hard has seemed in our experience to contribute to its development. Next come spoiled aliments, frosted or frozen turnips, beets, carrots, potatoes, apples, turnip tops, fermented grasses, musty hay, sun-exposed potatoes, putrid vegetables, and caterpillars on cabbages, tree leaves and other vegetables. Next come products that are highly nitrogenous, like vetches, alfalfa, sainfoin, clover, and the cakes of linseed, rape and cotton seed. Irritant plants such as colchicum, digitalis, yew, radish, etc., have been charged as causative agents. _Symptoms._ These are often difficult to distinguish from those of indigestion or acute lead poisoning, and they vary in different cases according to the severity of the attack. In the milder cases there may be loss of appetite and rumination, some tympany, arching of the back, uneasy movements of the hind limbs and tail, a disposition to leave the herd, grinding of the teeth, and frequent gaseous eructations. Some show a depraved appetite, picking up and chewing various non-alimentary substances. Somewhat more characteristic are the dry, hot muzzle, the hyperthermia of the body, the tenderness to pressure of the epigastrium, and the baked appearance and glistening surface of the fæces. In the more severe forms the suffering is increased and the nervous system participates in the disorder. The eyes are congested, fixed or rolled back, the pupils dilated, the vision appears to be abolished, the ears are pendant, if tied the subject attempts to get loose, if at liberty he moves steadily in some one direction regardless of obstacles or dangers, he bellows, pushes against walls or other obstructions and may seriously injure himself or others. There is, however, no mischievous purpose, he is simply impelled to blind motion, and no regard is had to anything which may be in his way. In some instances the nervous disorder is manifested by a sensitiveness of the skin, so that the animal shrinks when handled or pinched along the chine or back. Tremors is another marked symptom.