266 



FAMILY: EHIZOMASTIGIDiE 



Whitmore (19116), working in the Philippines with cultures of amoebae 

 isolated from water on agar plates, noted that a certain amoeba developed 

 a stage with three flagella. His figures also show forms with two and four 

 flagella. He gave it the name Tritnastigamceba philippinensis. The 

 amoeboid phase was 16 to 18 microns in diameter, while the cyst was 

 oval, and measured 13 to 14 microns by 8 to 12. In the flagellate phase, 

 with flagella slightly shorter than the body, the organism was elongated, 

 and measured 16 to 22 microns by 6*5 to 8 microns. As Dimastigamceba 

 gruberi may sometimes develop three, four, or more flagella, it is clear 



Fig. 121.^ — Amceboid Phase of Dimastigamceba gruberi off Agar Plate ( x 3,000). 



(Original.) 



1. Amceba showing nucleus with large central karyosome and peripheral granules and contractile 



vacuole (cv.). 



2. Encysted form showing double membrane of cyiist wall and three pores. 



3. Encysted form in which inner membrane has separated from the outer membrane excejit at the 



pores. 



that Whitmore was actually observing this species, his name Trimastig- 

 amceba becoming a synonym. From the work of Bunting (1922) it appears 

 that flagellates of the genus Tetramitus may also have an amoeboid phase 

 (see p. 310). 



4. Family: RHizoMASTiGiDyE Calkins, 1902. 

 This family includes certain free-living amoeba?, and possibly some 

 parasitic forms which possess a single flagellum. They are usually classed 



