Causes. Opinions are divided respecting the causes of this condition of the external ear. The one most in vogue refers it to mechanical injuries, such as blows, bruises, and the effects of polling or of robbing the ear. F. Bird has not recognised the operation of external violence, and when such has happened he has regarded it as only an accelerating cause? for he considers necessary a peculiar condition consisting in persistent congestion about the head and enlargement of the vessels. Flemming, on the contrary, believes an external hurt to be always the cause, mostly self-inflicted by the patient, who, from severe and painful feelings about the head, strikes it against hard objects. He would, however, not deny the existence of a predisposition to the morbid condition resulting from a cachectic state. Ferrus discovers the cause in the I long continued pressure and robbing, &c., to which the ear is submitted. Friedreich concurs with Bird, and adduces in illustration two cases of dementia in which an inflammatory swelling of the ear manifested itself along with evident signs of congestion, occurring after maniacal paroxysms. Belhomme believes it to spontaneously originate from the feeble, retarded, circulation, the consequence of paralysis, and from the proneness to stagnation in extreme parts. Again, Wallis, Leubuscher, and Schmalz, assume the presence of cachexia as necessary to the production of the swollen ear; whilst Riedel and Rupp are of opinion that external violence is in itself a sufficient cause.