204 



DISEASES DUE TO PROTOZOA 



fever. The causative microorganism may be found 

 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 

 flagellum on the forward end. They are from y^T 



2000 



to 



8000 



inch long and about two-thirds as wide. 



FIG. 59 



Trypanosoma gambiense. (From Calkins. Preparation by F. W. Balstack.) 



Trypanosomiasis. The next flagellate to cause dis- 

 ease is the Trypanosoma, two species of which are 

 pathogenic for man, causing a disease called try- 

 panosomiasis, or sleeping sickness. This affection is 



