The absence of Trypanosoma congolense from the lymph of an infected sheep.

The lymph draining the prefemoral lymph node of a sheep infected with Trypanosoma congolense was examined over a period of 10 days. Only six trypanosomes were detected in 1500 ml of this fluid during this time, in spite of the animal having about 65,000 organisms/ml in its blood. It is concluded that the suggestion that T congolense is a strict plasma parasite is essentially proven for this specific situation.