1908.] 



A Trypanosome from Zanzibar. 



base of the flagellum, and only a few isolated granules are scattered through 

 the remainder of the organism (Novy and MacNeal). 



Undulating Membrane. — Is not recognisable in the living organism. 



Flagellum. — Usually as long and often even longer than the cell itself. 



Motion. — All single and actively motile, traversing the field of the 

 microscope at great speed. Travel with the flagellum in rear or in front. 



Colonies or Aggregates. — Entire absence of the groups or rosettes, which 

 are so characteristic of the cultures of Trypanosoma lewisi and Trypanosoma 

 hrucei. The trypanosomes were all single and actively motile. 



Measurement of the Cultural Forms. 

 Length, including flagellum, 25 to 50 by 1*5 to 2 - 5 microns. 



Cultural Characters of Dr. Edington's Trypanosome. 

 A. Living, unstained. 



No difficulty is found in cultivating Dr. Edington's trypanosome. As- 

 early as the second day, if kept at 25° C, it is found to have greatly 

 increased in numbers. The single individuals are in active motion, the- 

 flagellum wildly waving, while the body slowly moves among the corpuscles. 

 Many dividing forms are seen with two or three flagella. Masses or 

 aggregations are also seen varying in size, from those composed of a dozen 

 individuals to those occupying a fifth of the field. These aggregation-forms 

 are all writhing and squirming, while the flagella at the periphery are 

 frantically waving. This incessantly moving mass, dotted over as it is with 

 many small bright vacuoles, makes a curious and beautiful microscopic object' 

 when brightly illuminated. 



On the third day the trypanosomes have multiplied to an extraordinary 

 extent. Huge aggregations are now seen, each filling up several fields of 

 the microscope. The individual trypanosomes are still actively motile. 

 Single, double, and small aggregations are also seen. 



By the seventh day they have reached the height of their growth and 

 begin to degenerate. 



After the twelfth day living forms can no longer be recognised in the 

 culture tubes. 



Size. — Dr. Edington's trypanosome, examined in the fresh living condition,, 

 varies considerably in size. Some of the large forms measure 32 microns in 

 length, whereas the smaller are only half that length, or even shorter. 



Shape. — So also in regard to shape, these cultural forms vary extremely. 

 Bound, oval, pear-shaped, and irregular forms are seen. Slender forms 



