AMOEBINA 



369 



nucleus one to many ; nucleus with a large central endosome and an 

 achromatic nuclear membrane; nuclear divisions mitotic and simul- 

 taneous; no solid food vacuoles; no contractile vacuole; with refrin- 

 gent granules. Cysts: spherical; thin-walled; devoid of glycogen and 

 of chromatoid bodies; 2 or more nuclei; parasitic. One species. 



Fig. 174. a-f, Dobellina viesnili (Bishop and Tate): a, b, uni- and multi- 

 nucleated stained amoebae, X2200; c, a trinucleate (stained) amoeba in 

 which the nuclei are dividing, X1760; d-f, stained cysts with 2, 4, and 6 

 nuclei, X1760 (Bishop and Tate); g, h, stained trophozoite and cyst of 

 Schizamoeba salmonis, X1070 (Davis); i, j, Hydramoeha hydroxena (Rey- 

 nolds and Looper): i, a heavily infected Hydra oligadis, X95; j, part of a 

 section of an infected host hydra, showing a trophozoite feeding on ecto- 

 dermal cells, X470; k, a stained individual of Paramoeba -pigmentifera, 

 with its nucleus in the center, X800 (Janicki). 



D. mesnili (Keilin) (Fig. 174, a-j). Uninucleate amoebae as small 

 as 3.6ju in diameter; multinucleate forms 20-25/x by 10-1 5yu; cysts 



