138 Trypanosome causing Disease in Man in Nyasaland. 



Table VIII. — The Percentages of Recoveries in various Animals infected with 

 the Naturally Infected Dog Strain and the Human Strain. 



Strain. 



Ox. 



Goat. 



Monkey. 



Dog. 



Rabbit. 



Guinea-pig. 



White rat. 



Naturally infected 



100 



100 



100 



21 







100 







dog 



















80 



























This shows the great difference in regard to action on animals which 

 exists between the Naturally Infected Dog strain and the Human strain,* 

 and if similar tables referring to other strains — for example, the Zululand 

 1913 Strainf — be compared, the same difference is found. It might be said 

 that this alone is sufficient to make it rank as another species, and, as 

 already mentioned, if this strain had been found among the wild game and 

 wild Glossina morsitans in Nyasaland, this would have been justified. It 

 was, however, only found in three chronically infected dogs, and so it is 

 thought best with our present knowledge to include it among the strains of 

 Trypanosoma brucei vd rhodesiense. 



If in the future it should be decided to give it specific rank the name 

 T. anceps is suggested. This name seems appropriate on account of the 

 uncertainty which exists as to the classification of this trypanosome. 



Conclusions. 



1. The Naturally Infected Dog strain is fatal to dogs, rabbits, and white 

 rats, but oxen, goats, monkeys, and guinea-pigs appear to be refractory. 



2. The Commission is of opinion that this is an aberrant or exceptional 

 variety or strain of the trypanosome causing disease in man in Nyasaland — 



T. brucci vd rhodesiense. 



* ' Roy. Soc. Proc.,' B, vol. 87, p. 35 (1913). 

 T Ibid. } B, vol. 87, p. 493 (1914). 



