2. If drum is ruptured, aspirate middle ear by catheter or by Moore’s method or both. =This is very important.= If no aspirating machine, use syringe and pump meatus and tube persistently. Dry meatus and keep well open. 3. Patient should be kept in bed if symptoms are marked, with light diet and bowels well open. 4. =Heat.=—Apply oil or other lubricant over whole side of face and head and apply heat by means of “therapeutic” lamp intermittently. Thirty minutes light on and fifteen minutes light off. The light-heat (any electric lamp with reflecting shade will do) is much better than hot water bottle or electric pad or sand bag. The heat must be kept going day and night if symptoms are marked until the pain has entirely subsided. Heat is most efficient in the early stages. After symptoms are well marked, the ice pack is more desirable. 5. If drum is not ruptured, heat may be applied by means of Deason’s continuous irrigating cup. Start at 116° F. and gradually increase to 123° F. if patient can bear it. =Surgical.=—If drum has not ruptured and symptoms continue, it is best to make free incision of drum,—keep open and apply (2) above. =Indications for Mastoid Operation.=—There are no definite signs, symptoms or tests that will determine positively when operation should be done. If the above non-surgical methods are practiced, few cases will require operation, but many will develop into chronic mastoiditis and so it is very difficult to decide whether a mastoid operation should or should not be done. It is best to explain thoroughly the possible complications to the patient and relatives and request them to assume responsibility. Mastoid operations are attended by very little danger when properly done. =Signs and Symptoms Suggesting Operation.=—Acute otitis media with mastoiditis. (1) Persistent pain and swelling not relieved by non-surgical treatment. (2) Marked protruding of posterior wall or meatus. (3) Marked tenderness, swelling and discoloration above ear or over tip of mastoid. These with temperature of more than 102° usually are enough to demand immediate drainage. (4) Any evidence of extension of pus under skin of neck below tip. A positive indication for drainage. (5) Any indications of brain or meningeal involvement such as very marked and persistent headache, partial or total loss of consciousness, etc. (6) Indications of labyrinthine involvement such as marked vertigo, etc. (7) Sudden cessation of discharge means obstructed drainage from middle ear or from mastoid into middle ear and if drainage cannot be restored by aspiration, this means operation. (8) The whole clinical picture must be carefully considered at all times. Take no chances. Advise operation before someone else finds it too late. Chronic Mastoiditis =Cause.=—Always from unsuccessfully treated acute form or from chronic suppurative otitis media.