MASTIGOPHORA 



751 



and Hemorproteus ziemani with resulting confusion in the study of 

 trypanosomes and hemocytozoa, and it is only recently that the error 

 has been generally ackowledged. 



FIG. 173. TRYPANOSOMA AVIUM IN CULTURE ON BLOOD AGAR. (X 1500.) (After 

 Novy and MacNeal. MacNeal, "Pathogenic Microorganisms," published by P. 

 Blakiston's Sons & Co.) 



Trypanosoma gambiense (Sleeping Sickness). Two names have 

 been given to the disease caused by this parasite, both of which are 

 now recognized as stages in one and the same infection, human tryp- 

 anosomiasis: they were trypanosome fever, and sleeping sickness. It 

 is a chronic infection characterized by fever, lassitude, weakness, 

 wasting, and, in its terminal stages, by a. protracted lethargy. Sleep- 

 ing sickness and trypanosome fever had long been known in tropical 

 Africa, and the disease at present is widespread and the cause of 

 tremendous mortality. It is estimated that one hundred thousand 

 deaths accurred during the ten years ending in 1910. It is endemic 



