Cerebral embolism and thrombosis and their sequelæ, infarction and softening, give rise to corresponding symptoms, according to the seat of the lesion, and like lesions of the blood vessels predispose to subsequent attacks. _Diagnosis_ is based largely on the appearance, usually sudden but sometimes slow, of a more or less profound unconsciousness, attended or followed by paralytic troubles. The history of the case may assist, any blow on the head, or sustained by falling, striking a wall or post, or wearing a yoke, is to be noted. Any extraordinary exertion or excitement must be considered. Any sign of injury about the head; the congestion of the cephalic mucous membranes in contrast with the pallor of _shock_; the onset of the attack without convulsions (or with them as in epilepsy); the deep coma indicating cerebral hæmorrhage or narcotic poisoning; the absence of the odor of alcohol, opium, or other narcotic from the breath; the turning of the eyes to one side and the inequality of the pupils on the two sides; the turning of the head to the same side as the eyes; the slow, labored, usually stertorous breathing; the slow, full, soft pulse; the occasionally rigid condition of the muscles and finally the paralysis, hemiplegic, and less frequently monoplegic or paraplegic, make up the diagnostic picture. _Uræmia_ and _diabetic coma_ may be excluded by examination of the urine, _pulmonary apoplexy_ or _œdema_ by the predominance of respiratory troubles, and fulminant _anthrax_ by the examination of the blood and by the fact that this disease does not prevail in the locality. _Treatment_ is very unsatisfactory in the lower animals, as the disease is very fatal, and unless recoveries are complete, they are not pecuniarily desirable. It is only in the slighter cases, therefore, that treatment can be recommended. At the very outset nothing is better than a full bleeding in a large stream from the jugular vein or temporal artery. Ice, snow, or cold water should meanwhile be applied to the cranial region. Absolute rest should be given, any harness that would impede circulation or respiration removed, and hot water or stimulating embrocations applied to the limbs. When consciousness returns and the patient can swallow, an active purgative may be administered, or barium chloride or eserine may be given subcutem. Any recurring heat of the head may be met by renewal of cold applications, and the force of the circulation may be kept in check by small doses of bromides or aconite. In case of the formation of a clot, iodide of potassium and other alkaline agents may be resorted to. Quiet and the avoidance of all excitement together with a laxative non-stimulating diet must be secured throughout. A course of vegetable or mineral tonics and an occasional blister to the side of the neck may prove a useful sequel. CEREBRAL HYPERÆMIA. MENINGO—ENCEPHALIC CONGESTION.