TRYPANOSOMA 



483 



about 25 per cent, of wild rats in almost all parts of the world. It is found 

 less frequently in tame rats, especially in the white variety. It occasionally 



FIG. 146 



Trypanosoma Lewisi (Kent). From the blood of a rat. (Kempner and Rabinowitsch.) 



FIG. 147 



Agglutination of Trypanosoma Lewisi. (Laveran and MesniL) 



produces sickness and death and even small epidemics, but generally 

 it is found in apparently healthy animals. A morphologically similar 

 trypanosome is found in hamsters, but as neither variety will ^ro\v in 



