Remarks on Mr. Plimmer s Note on Gambian Fever, etc. 317 



Fever parasites, and since May, 1904, three strains of trypanosomes obtained 

 by me from cases of Sleeping Sickness which died in Liverpool. 



I have been able to inoculate rats directly with cerebro-spinal fluid from 

 my cases. I have, therefore, been able to compare the trypanosomes derived 

 from many different strains. 



After a comparison of over 1000 experiments, nearly 600 being on rats, I have 

 had to conclude that all the parasites are identical with T. gambiense. Eats 

 inoculated with a Sleeping Sickness strain show parasites in their blood and 

 finally succumb to the infection in the same way as do their controls infected 

 with a Gambian Fever strain. No symptoms of paraplegia have been observed 

 in any of the rats. Post-mortem. — The same enlargement of the spleen and 

 some enlargement of the glands are observable. 



Mr. Plimmer reports that morphologically the parasite of Gambian Fever 

 differs from that of Sleeping Sickness in similar animals, the former being 

 larger and more easily stainable than the stumpy, badly staining trypanosomes 

 with large vacuoles of Sleeping Sickness. 



I am not in accord with these observations, after numerous observations 

 in parallel series with each strain of trypanosome, i.e., same species of animal 

 and same number of passages, and passage through same species of animals. 

 I can detect no marked difference. Both stumpy and large forms are met 

 with, vacuoles are most often observed in films made from very serous blood 

 from exudates, and are often present in films which are allowed to dry slowly 

 or are improperly fixed. 



Experiments were made by inoculating rats and larger animals with the 

 Gambian Fever trypanosomata, and, after the appearance of the parasite, 

 injecting them with Uganda or Congo Sleeping Sickness organisms, and vice 

 versa, using controls in all cases. From a comparison of the blood of these 

 animals with their controls, both in fresh and stained films it was impossible 

 to determine which parasite was the Gambian one. 



Professors Laveran and Mesnil, and the members of our Congo Expedition, 

 from a comparison of the tiypanosomes of Gambian Fever and Sleeping 

 Sickness, have also been unable to detect any differences. 



Professor Laveran, who has had the opportunity of working with Gambia 

 Fever and Uganda Sleeping Sickness parasites, in a private communication 

 which he allows me to make public, states that he has never observed 

 symptoms of paralysis in his series of rats infected with these strains. 



T, therefore, do not feel that Mr. Plimmer is justified in concluding that 

 Gambia Fever and Sleeping Sickness are distinct diseases. 



vol. lxxviii. — B. 



