DO U RISE OR MIL AD IE DU C'OIT 



45 



The blood of all these mice was examined before inoculation and in none of them 

 were found the trypanosomata with which a small percentage of these field mice are 

 naturally infected. Numerous blood preparations have been made subsequent to the 

 inoculation, trypanosomata being found in but one preparation taken just before 

 death. 



November 15, 1907. In all, sixty native ' white posted ' mice have been subjected 

 to inoculations. In my foregoing observations on mice, I have mentioned in detail 

 the case of one mouse dying on the seventh day after inoculation and the finding of 

 six trypanosomata in a blood preparation taken an hour before death. In view of all 

 subsequent failures to infect these animals, I think it probable that the parasites were 

 of the non-pathogenic variety found in about 15 per cent of these native mice. The 

 lethargic condition noted in a few of the inoculated mice I have since rarely observed 

 in control mice, in the first few days of their captivity. 



Table xi. — Showing the presence or absence of Trypanosomata. 



Explanation— The nmnbers in the columns represent the number of preparations, fresh or stained, that 

 have been examined. Trypanosomata being present in those under the positive sign, and absent in 

 those under the negative sign. 



