136 Sir D. Bruce and others. Trypanosome 



Sheep. — Two sheep were inoculated. One recovered; the other died after 

 64 days, probably of the disease. 



Monkey. — This trypanosome has little or no effect on monkeys. Twenty- 

 seven were used as experimental animals. Twenty-one proved refractory ; 

 the remaining six were returned as " Eecovered " after being under observa- 

 tion for several months. 



Dog. — This strain has become, after several passages, virulent to dogs. 

 Twenty-eight were used for experiment. Nineteen died, on an average, in 

 36 - 8 days (11 to 102); four never showed trypanosomes in their blood ; and 

 five recovered. The post-mortem appearances are the same as those found in 

 Nagana : enlargement of the spleen, gelatinous oedema about the vessels at 

 the base of heart, petechias of mucous membranes, and corneal opacity. 



Babbit. — Only two were inoculated. Both died, one after 109 days, the 

 other after 256 days. Both showed corneal opacity and presented the same 

 symptoms as those described in Nagana rabbits, but in a much milder 

 degree. 



Guinea-pigs. — The guinea-pig, like the monkey, is almost refractory to 

 this strain. Twenty-one animals were inoculated. Nineteen of these proved 

 refractory, and the remaining two only showed trypanosomes on one occasion 

 and appear to have recovered. Bats inoculated with their blood remain 

 unaffected. 



White Rat. — This strain is virulent to rats. Forty-eight were inoculated, 

 and all died, on an average, in 30 - 8 days (7 to 94), with enormous enlarge- 

 ment of spleen, and the blood swarming with trypanosomes. 



Comparison of the three Strains of the Trypanosome of the Naturally 

 Infected Dog Strain in Begard to their Virulence towards 

 various Animals. 



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

 of the three Strains. The letter B means that the animal is refractory. 



Strain. 



Ox. 



Groat. 



Sheep. 



Monkey. 



Dog. 



Rabbit. 



Guinea-pig. 



White rat. 



I 



E. 



R. 



64 



E. 



29 



182 



E. 



29 



II 









E. 







E. 



30 



III 





R. 





E. 



59 





E. 



46 



