In all probability the animal has in every case been more or less unwell, except in those attacks of indigestion resulting from progressive poisoning during the course of a meal, such as occur when toxic plants like belladonna, veratrine, colchicum, poppies, tobacco, hemlock, etc., have been eaten. In such temporary abnormal states movement of the rumen is partly abolished, or at least is markedly retarded, and, as a consequence of vaso-motor disturbance, the mucous membrane is probably not so abundantly covered with mucus nor so freely irrigated with secretion, as usual. Under these conditions, if the animal, which may appear perfectly well, is allowed to partake of soft, wet, fermentescible food, gaseous indigestion is very likely to develop. Cultivated grasses, like lucern, sainfoin, clover, and especially grasses grown on artificially manured fields, are regarded as particularly liable to cause gaseous indigestion. This conclusion seems justified by experience, particularly by the fact that young shoots or young, tender after-growths are very liable to fermentation. This exaggerated tendency to fermentation of tender grasses has even been held exclusively responsible for indigestion, and the cessation of peristalsis in the rumen has been considered a secondary phenomenon, due to distension. Whether atony of the rumen be the primary condition and abnormal fermentation secondary or inversely, whether fermentation be primary and atony secondary, is not of importance; for either view may be adopted without altering the results, and without the theory being invalidated by the objection that other animals subjected to similar influences had not contracted the condition. We have already drawn attention to the importance of the condition of the animal’s health for the time being. Digestive peristalsis being diminished, eructation, admixture of food in the rumen, and its onward movement being impeded, fermentation proceeds rapidly. As a consequence the rumen becomes distended, and, cause and effect changing places, the distension in its turn arrests peristalsis, which had previously only been checked.