io THOMPSON YATES AND JOHNSTON LABORATORIES REPORT 
2. None of the human trypanosomes seen, whatever their source, have presented 
any morphologic appearance incompatible with Trypanosoma gambiense. 
3. The parasites seen in rats inoculated with the cerebro-spinal fluid of cases 
admitted to the hospital for sleeping sickness are the same as those seen in rats 
inoculated with the blood of cases of either sleeping sickness or simple trypanosomiasis. 
4. The organisms seen in the blood of rats inoculated with trypanosomes from 
any ol the three indicated sources have up to the present shown no differences from 
those observed in animals infected with Trypanosoma gambiense. 
We have observed the extraordinarily long forms with prolonged flagella, and 
the stumpy forms with short flagella described as occuring in animals inoculated with 
the Gambian parasite. 6 
We have, therefore, no reason to suppose that the organisms seen by us in the 
Congo are other than Trypanosoma gambiense. 
References 
1. Christy, The Epidemiology and Etiology of Sleeping Sickness in Equatorial East Africa, with Clinical Observations, Royal 
Society Sleeping Sickness Commission, Report III, November, 1903. 
2. Laveran and Mesnil, Des Maladies a Trypanosomes, leur Reparition a la Surface du Globe, Janus, August 15, 1903, 
pp. 395-402. 
3. Bruce, Royal Society Sleeping Sickness Commission, Report I, August I, 1903. 
4. Castellani, Royal Society Sleeping Sickness Commission, Report I, August, 1903. 
5. {Cruse, Ueber das Trypanosoma Castellani den Erreger der Schlafkrankheit. Simmgsberichten der Neiderrhein Gese/lsc/iatt 
f. Natur. u. Heilkunde xu Bonn, May, 1903. 
6. J. E. Dutton and J. L. Todd, First Report of the Trypanosomiasis Expedition to Senegambia, Liverpool School of Tropical 
Medicine. Memoir IX. 
