FLUID WHICH has accumulated in the mastoid and middle ear cleft, behind an intact tympanic membrane, theoretically, might find an escape from the confines of these spaces by two possible routes: down a patent eustachian tube, or by absorption into the submucosal plexus of lymph and blood vessels. The method whereby the eustachian tube may serve as a channel for the egress of fluids which have accumulated in the middle ear cleft has been studied.2 It was noted that in order for the tube to act as an escape route, the pressure within the mastoid and middle ear spaces must be at least equal to the pressure in the nasopharynx. If, however, the pressure within the mastoid air cells and tympanum is lower than the pressure in the nasopharynx, then any fluid which is partially filling these spaces may remain for an undetermined period of time. Some authors feel