1. Of the domestic animals sheep, cattle, goats and equines are susceptible in that order of frequency and severity.
2. Three main forms of uitpeuloog are recognized-the ophthalmic, encephalitic and cardiac forms. The symptoms are described.
3. The pathognomonic pathological lesions are thrombo-endophlebitis and thrombo-endarteritis with encephalomalacia.
4. It is shown that the immediate cause of the disease is the invasion of an aberrant host by first stage larvae of Gedoelstia hiissleri, and G. cristata Type I and Type II of the family Oestridae.
5. The portal of entry of the larvae is he eye. Two cases of the disease, one being the fatal encephalitic form, were produced by the supracorneal and conjunctival instillation of larvae dissected from the abdomen of a captured gravid female G. cristata Type I.
6. Three recognizable types of larvae, Types A, B and C, are described as emanating from G. hiissleri and G. cristata Type I and Type II respectively.
7. The role of blue wildebeest and hartebeest in the aetiology is discussed and adult flies were reared from larvae collected from the nasal cavities of these species of game.
8. Attention is directed to the fact that in contra-distinction to the susceptible species of domestic animals no macroscopic pathological lesions are produced in game.
9. The epizootiology of the disease is discussed.
10. A suggested pathogenesis in domestic animals and game is outlined.
11. The presence of unidentified species of Oestridae in the trachea of game is recorded.