causing Disease in Man in Nyasaland. 



137 



Table V. — The Average Duration, in Days, of the Disease in various Animals 

 of the three Strains combined. The letter K stands for " refractory." 





Ox. 



Goat. 



Sheep. 



Monkey. 



Dog. 



Eabbit. 



Guinea- 

 pig- 



White 

 rat. 



Average duration, 



in days 

 Number of animals 



employed 



E. 



4 



E. 

 21 



64 

 2 



E. 

 27 



37 

 19 



182 

 2 



E, 

 21 



31 

 48 



Table VI. — The Percentages of Eecoveries in various Animals infected with 

 the Naturally Infected Dog Strain. Three strains combined. 





Ox. 



Goat. 



Sheep. 



Monkey. 



Dog. : Eabbit. 



Guinea- 

 pig- 



White 

 rat. 



Number of animals 

 employed 



100 

 1 



100 

 7 



50 i 100 

 2 | 6 

 * 



21 

 24 





 2 



100 

 2 





 48 



From Table VI it will be seen that the Naturally Infected Dog strain is 

 not fatal to oxen, goats, monkeys, or guinea-pigs, whereas it killed 79 per cent, 

 of the dogs and 100 per cent, of the white rats. 



compaeison of the trypanosoma of the naturally infected dog strain 

 with the trypanosome causing disease in man in nyasaland 

 (Trypanosoma brucei vel rhodesiense). 



Table VII. — The Average Duration of Life, in Days, of various Animals 

 infected with the Naturally Infected Dog Strain and the Human Strain. 

 The letter E stands for " refractory." 



Strain. 



Ox. 



Goat. 



Monkey. 



Dog. 



Eabbit. 



Guinea-pig. 



White rat. 



Naturally infected 



E. 



E. 



E. 



37 



182 



E. 



31 



dog 

















Human 



134 



42 



26 



34 



28 ' 



67 



30 



It is curious that this strain, although evidently harmless to oxen, goats, 

 monkeys, and guinea-pigs, is quite as virulent as the Human strain to dogs 

 and rats. 



