Page:Tropical Diseases.djvu/228

Bruce's Classification of Pathogenic African Trypanosomes
	Form	Cytoplasm	Micro- nucleus	Undulating Membrane	Movement	Development in Tse-Tse	Susceptible animals
A. Trypanosoma Brucei Group, including T. Brucei—T. Gambiensi T. Evansi T. Equiperdum	Polymorphic including short and stumpy forms	Contains dark- staining granules	Small and as a rule, at some distance from posterior end	Well developed and in bold folds	Active	Completed in salivary glands	Many species of mammals
B. Trypanosoma Pecorum Group, including T. Pecorum T. Simiæ	Mono- morphic and small	Non- granular	Prominent and sub- terminal	Well developed	Active	Completed in pro- boscis and hypo- pharynx. Never found in salivary glands	Cattle—very fatal to pigs
C. Trypanosoma Vivaz Group, including T. Vivax T. Capræ T. Uniformi	Mono- morphic	Non- granular	Large and terminal	Little development and simple	Very rapid	Completed in pro- boscis and hypo- pharynx. Never found in salivary glands	Affects only horse, cattle, goats and sheep. Ordinary laboratory animals immune