Middle-ear effusions have been produced following eustachian tube obstruction in guinea pigs. This was achieved by plugging the pharyngeal orifice of the tube by an atraumatic lateral transpalatal incision. General anaesthesia was used throughout the entire procedure. The presence of fluid in the middle-ear cavity was determined by observing:

(a) The appearance of pallor of the drum.

(b) Retraction of the tympanic membrance.

(c) Cloudiness of the tympanic bullae on radiographs obtained at weekly intervals, confirmed by:

(d) Subsequent myringotomy.

Serial smears of the induced effusions showed an absence of chronic inflammatory cells except in the case of one animal which developed bacterial otitis media. The presence of secretory cells was demonstrated in the actual epithelial layer and lamina propria but no discrete glands were found. Squamous metaplasia of the lining of the middle-ear cleft was noted. The fluid from the tympanic cavity appeared watery, faintly turbid and non-mucoid, and resembled the serious type of effusion found in man.

The purpose of this paper is to show that satisfactory results following mastoidectomy can be obtained for the problem of chronic serous otitis. The success of the simple mastoid operation or mastoidectomy with facial recess approach and the subsequent increased aeration of the mastoidantral-attic-middle-ear complex is to be suggested when the repeated use of myringotomy tubes alone is not the answer to chronic serous otitis. It is chronic negative pressure due to eustachian tube dysfunction that leads to irreversible mastoid disease.

Seven cases of mastoidectomy for chronic serous otitis media are presented. All cases had adequate conservative medical and surgical treatment over a period of years for chronic serous otitis before mastoidectomy was considered. The clinical history, as well as lateral mastoid X-ray, was used in diagnosing irreversible mastoid disease.

Total en bloc removal is the ideal surgical treatment for glomus jugulare tumours. Efforts to accomplish this have been made periodically since shortly after this tumour was first identified in the early 1940s. A method of removal using a combined approach through the neck and temporal bone is described here. This method is preceded by pre-operative irradiation therapy and on occasion by embolization. The early results obtained using this method in 19 patients are reported.