Early in the present century Looss observed in Egypt that a heavy meat diet was unfavorable for certain parasitic worms. Twenty years later Ackert noted in Trinidad, British West Indies, that a diet lacking meat was favorable for helminths, especially the human ascarid, Ascaris lumbricoides, which in some instances formed infestations of 100 or more worms in persons whose principal diet was bread and tea. In another decade, Hegner conducted tests which showed that a carbohydrate diet favored the multiplication of certain human protozoan parasites. However, several elderly people who may have been free from parasites were maintaining that they had better health while on meatless (vegetarian) rations, although they did partake of such animal products as milk, butter, cheese, and fish.