In cases of =gastric vertigo= an active cathartic, followed by smaller laxative doses or a laxative diet and a course of bitters may prove useful. Such cases should never be worked on a full stomach but should be left at rest for at least an hour after a meal. In =aural vertigo= special attention must be given to the throat, and external ear. Bromides may often be useful, and sometimes benefit may be derived from an occasional blister or light firing back of the ear. In =cœnurus cerebralis= in sheep the only resort is to trephine and remove the parasite. CONCUSSION OF THE BRAIN. Definition. Causes: leaps, trips, falls, blows. Symptoms: fall, insensibility, flaccidity, suspended respiration, tumors, vomiting, recovery, signs of cerebral congestion. Pathology: anæmia followed by congestion. Diagnosis: from fracture, epilepsy. Treatment: quiet, rubbing of limbs, ammonia, cold to head, or heat; for congestion, bromides, depletion, ice pack, derivatives. _Definition._ Concussion is the condition produced by mechanical jar or shock of the cerebral mass, and manifested by modification of the brain functions of any grade from a simple dazed condition to that of complete unconsciousness. _Causes._ The most familiar cause is the stroke of the butcher’s pole axe, producing sudden and absolute insensibility. A horse in leaping, trips and falls on his head or running against a wall sustains a concussion, which leaves him for some seconds without any signs of life. The same will happen to other animals, but above all to rams which in their combats, back for a number of yards and running together meet with a shock from the effect of which even their thick skulls cannot save them. Other blows upon the head operate to the same end. _Symptoms._ Concussion is manifested by different grades of symptoms. At first there is usually a fall with complete insensibility. The animal lies flaccid, utterly insensible to external irritation and there is suspension of respiration. The heart continues to beat and a frequent weak pulse may be often detected. In slight cases, breathing may be reestablished at the end of a minute or two, with muscular tremors and movements of the limbs; then the animal rises, shakes his head, neighs, and walks at first unsteadily and afterward with greater and greater firmness. In vomiting animals, emesis occurs. In some cases this may be followed, after an hour or two, by signs of congestion, heat of the head, redness of the eyes, irritability, or dullness and stupor and perhaps muscular twitching. This may improve or it may terminate in death preceded by spasms, general convulsions, rolling of the eye balls, and stupor or coma with general muscular relaxation.