FAMILY: DIMASTIGAMCEBIDvE 261 



from human faeces by Schardinger (1899), who named it Amoeba gruberi. 

 Wasielewski and Hirschfeld (1910) showed that an amoeba which they 

 called A. Umax at certain stages developed two fiagella. A similar 

 observation was made by AlexeiefE (1912^) on an amoeba referred to as 

 A. punctata (Dangeard). Martin and Lewin (1914) showed that a 

 soil amoeba, which they called Vahlkampfia soli, readily developed two 

 flagella when an agar plate containing the encysted forms was flooded 

 with tap water containing 025 per cent. NaCl and 0-05 per cent. MgS04. 

 Wherry (1913), working with a similar amoeba, could produce the trans- 



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4 

 Fig. 119. — Parasitic Amceb.e of the Genus Paramceba. (After Janicki, 1912.) 



1. Free form of P. pigmentifera with two nuclei (X 1,800). 



2. Dividing form of P. chcstognathi ( x 2,700). 



3. Flagellate stage of P. pigmentifera ( X 3,650). 



4. Dividing flagellate form of P. pigmentifera (x 3,650). 



formation by merely diluting a loopful of liquid egg-medium culture of 

 the amoebse with several loopfuls of distilled water, observations which 

 were confirmed by Wilson (1916). In all these cases the flagellates had 

 two flagella of approximately equal length, and traceable to two blepharo- 

 plasts in the cytoplasm or to the nuclear membrane. It is probable that 

 all these amoebae belong to the species which was first isolated from human 

 faeces by Schardinger (1899), who called it A. gruberi. On account of 

 its flagellate stage, it was placed in a new genus, Noegleria, by Alexeieff 

 (1912), who later (1912a) came to the conclusion that it belonged to the 



