1. A descriptionption of plunging ranulas as seen in the South African Bantu has been given. 2. A new and simple therapeutic approach exploiting the photo-electric emission from an irradiated heavy metal (Bi) injected into the ranula has been evolved and is descriptionbed in detail. 3. The histological changes after treatment show destruction of the epithelial lining, degeneration of the collagen, and endarteritis of the bloodvessels in the wall. 4. Tbe embryology of these cysts has been discussed and it has been suggested that Thompson's theory of the branchiogenic origin of these cysts is the most likely explanation for these extensive swellings seen in the Bantu. 5. The physical basis for the therapeutic results obtained has been elucidated and shown to be in good agreement with previously-established experimental data. 6. There have been no failures in a consecutive series of 25 cases treated by this method over a period of 3 years.
The evolution of myocardial infarction in a patient with repeated attacks of prolonged myocardial ischaemia has been followed up clinically and illustrated by the respective E.C.G.'s. Some aspects of treatment have been shortly discussed.