218 



DISEASES DUE TO PROTOZOA 



almost anywhere in the body, but chiefly in the. 

 spleen, whence it may be obtained by puncture with 

 a needle. It is said that bed-bugs and mosquitoes 

 transmit the disease. The protozoon responsible, Leish- 

 mania Donovani, is an ovoid or circular or comma- 

 like mass with two nuclei, and one moderately long 



FIG. 61. Trypanosoma gambiense. (From Calkins. Preparation 

 by F. W. Balstack.) 



flagellum on the forward end. They are from 12 ooo 

 to g-oVo mc h l n an ^ about two-thirds as wide. See 

 Fig. 60. 



Trypanosomiasis. The next flagellate to cause dis- 

 ease is the Trypanosoma, two species of which are 

 pathogenic for man, causing a disease called trypano- 

 somiasis, or sleeping sickness. This aft'ection is com- 



