In all acute or severe cases, there is anorexia, suspension of rumination, and the normal movements of the compressed bowels seem to be largely impaired, though the anus is protruded and a little semi-liquid fæces or urine may be expelled at intervals. The breathing is accelerated, short, and labored. The nostrils are dilated, the nose extended, the face anxious, the eyes bloodshot and the back arched. Froth may accumulate around the lips, or the mouth may be held open with the tongue pendent. Sometimes a quantity of gas may suddenly escape with a loud noise, but without securing permanent relief. The heart beats are violent and accelerated, the pulse increasingly small and finally imperceptible, and the visible mucous membranes are congested and cyanotic. Pregnant females are very liable to abort. When the right flank as well as the left rises to the level of the lumbar spines death is imminent, and this may take place as early as fifteen or thirty minutes after the apparent onset of the attack. Death may result from nervous shock, from suffocation, or from the absorption of deleterious gases, or from all of these combined. In the less acute cases the animal may live several hours before the affection terminates in death or recovery. As a rule he stands as long as he can and finally drops suddenly, the fall often leading to rupture of the diaphragm or stomach, to protrusion of the rectum, or the discharge of ingesta by the mouth and nose. In still slighter cases relief comes through vomiting or more commonly through frequent and abundant belching of gas, the swelling of the flanks subsides, rumbling of the bowels may again be heard, and usually there is a period of diarrhœa. _Gases present._ When the rumen is punctured before or after death so as to give exit to the gas in a fine stream it proves usually more or less inflammable, the lighted jet burning with a bluish flame. The usual inflammable ingredients are carbon monoxide, hydrogen carbide (marsh gas) and hydrogen sulphide, yet the relative proportion of the gases varies greatly with the nature of the food and the amount of gas evolved, carbon dioxide being usually largely in excess. The following table serves to illustrate the variability: