^^4 SCIENCE IN AFRICA 



brain vaccine. A further virus disease of horses, ephemeral fever, 

 was studied and its nature determined. 



Pioneer work has been done at Onderstepoort on worm infec- 

 tions, particularly in sheep, by Theiler, Veglia, Monnig, le Roux, 

 Ortlepp and others. The life histories of several important para- 

 sitic worms were worked out and methods of treatment devised. 

 The treatment of wireworm infection {Haemonchus contortus) by 

 means of a mixture of copper sulphate and sodium arsenite was 

 so effective and became so popular, that the issue of this powder 

 assumed collossal dimensions; 25,000,000 doses and more have been 

 issued in one season. Quite recently a further notable success was 

 achieved when the dreaded nodular worm infection of sheep 

 Oesophagostomum columbianum, was successfully treated by Monnig 

 with a mixture of copper tartrate and copper arsenate; millions 

 of doses of this powder are now being issued annually. The role 

 of Schistosoma in sheep and other domestic animals was also eluci- 

 dated. 



Nutritional problems have figured largely in the research pro- 

 gramme of Onderstepoort (Theiler, Green, Malan, and others). 

 The importance of phosphorus deficiency was first determined in 

 South Africa, and far-reaching results were obtained. Further 

 study of the minerals in nutrition led to the solution of the 1am- 

 siekte problem which for so many years puzzled scientists in the 

 Union {see Chapter VI). Botulism in horses, ostriches, and other 

 animals was also studied and brought under control. In connec- 

 tion with deficiency diseases, many detailed studies on pathology, 

 especially of bones, have been made by Theiler. 



Poisonous plants have received miuch attention at Onderste- 

 poort. The etiology of diseases like gousiekte in sheep (caused by 

 Vangueria pygmna), vermeersiekte (vomiting disease, caused by 

 Geigeria spp.), jaagsiekte in horses (caused by Crotolaria spp.), etc., 

 have been worked out, and the peculiar relation between hairless- 

 ness in goat kids and poisonous plants [Chrysocoma tenuifolia) eaten 

 by the mother ewes was shown by Steyn. 



Among successes in the eradication of diseases in South Africa 

 may be mentioned the following. Pleuro-pneumonia has been 

 stamped out completely. Foot-and-mouth disease, which quite 

 recently threatened the territory, was kept out by a vigorous cam- 



