ANIMAL PARASITES. 113 



Trypanosomiasis, or the infestment of the 



blood with flagellated protozoa, trypano- 

 Trypanosoma . . . 



P somes, IS common among many varieties 



of animals, viz., fish, birds, horses, cattle, 



etc. In some it is productive of disease, 

 in others not. Different varieties of trypanosomes, 

 probably, are the cause respectively of the disease of 

 horses and cattle in India and the Philippine Islands 

 known as surra, and of the tsetse-fly disease or nagana 

 of South Africa. In man the parasite is associated 

 with the dreadful African ^'Sleeping-sickness," and is 

 transmitted by the stinging fly glossina. 



Dum-Dum fever, or Tropical Spleno- 

 DuM-DuM megaly, is a protozoan infection prevalent 

 Fever. among the natives of India, Assam, Ceylon, 



China and Egypt. The parasite, Donovan- 

 Leishman bodies, has been found widely distributed 

 in the body. The manner of transmission is unknown. 



Protozoa which increase their numbers 

 Plasmodium by the production of spores or seeds are 

 Malarle. called sporozoa. When sporozoa live at 



the expense of the red blood-cells of an 

 animal they are especially distinguished by the signifi- 

 cant name hcemosporidia. To the latter class belongs 

 the Plasmodium of malaria. The plasmodium malariae 

 (Laveran), of which there are three varieties, lives and 

 develops within, and at the cost of, the colored cor- 

 puscles of the blood. When first seen it appears as a 



8 



