The importance of the time factor has been recognized since the inception of radiotherapy. Coutard, in the treatment of patients with cancer of the larynx, experimented with overall treatment times ranging from two weeks to seventy days (6). Many other authors have since reported on the influence of the time factor (3, 8, 11, 14), and an excellent review of this subject has been made by Cantril (5). The size of the area of skin or volume of tissue irradiated has also been recognized as an important factor in the reactions elicited, with the tolerance decreasing as the volume irradiated increases. A study of the literature, however, discloses that, at least in carcinoma of the larynx, more emphasis has been given to the time factor than to the volume factor. In the management of squamous carcinoma in this area, preservation of a normal voice is second only to preservation of life. Total laryngectomy for early cord cancer would be almost 100 per cent curative; partial laryngectomy produces 85 to 90 per cent...