EUGLENOIDINA 233 



shaped during movement; the majority possess a single anterior 

 flagellum (with the exception of Eutreptia and Euglenamorpha) ; 

 green chromatophores (except one genus) and stigma occur, though 

 in some cases absent; haematochrome often coexists; metaboHc 

 products oil and paramylon; asexual reproduction by longitudinal 

 fission in either active or resting stage; mostly freshwater inhabit- 

 ants. 



Genus Euglena Ehrenberg. Short or elongated spindle, cylindrical, 

 or band-form; pellicle usually marked by longitudinal or spiral 

 striae; some highly plastic with a thin pellicle; others regularly spi- 

 rally twisted; stigma usually anterior; chromatophores numerous and 

 discoid, band-form, or fusiform; pyrenoids may or may not be sur- 

 rounded by starch envelope; metabolic products paramylon bodies 

 which may be two in number, one being located on either side of 

 nucleus, and rod-like to ovoid in shape or numerous and scattered 

 throughout; contractile vacuole small, near reservoir; asexual repro- 

 duction by longitudinal fission; sexual reproduction reported in 

 Euglena sanguinea; common in stagnant water, especially where 

 algae occur; when present in large numbers, the active organisms 

 may form a green film on the surface of water and resting or en- 

 C3'sted stages may produce conspicuous green spots on the bottom 

 of pond or pool; in fresh water. Numerous species. 



E. pisciformis Klebs (Fig. 101, a). 25-30^ by 7-10m; spindle-form 

 with bluntly pointed anterior and sharply attenuated posterior end; 

 slightly plastic; highly active; paramylon indistinct; a few chroma- 

 tophores lateral and discoidal ; each with 2 pyrenoids ; flagellum fairly 

 long. Johnson observed that division into 2 or 4 individuals occurs in 

 enc3^sted forms. 



E. viridis Ehrenberg (Fig. lOl, h). 50-60/x by 14-18/x; anterior 

 end rounded, posterior end pointed; spindle-shaped during motion, 

 highly plastic when stationary; pellicle obliquely striated; chromato- 

 phores more or less band-form, arranged in a stellate form; nucleus 

 posterior; nutrition holophytic, but also able to carry on saprozoic 

 nutrition, during which period chromatophores degenerate. Multi- 

 plication in thin-walled cysts (Johnson). 



E. acus E. (Figs. 24, h; 101, c). 50-200ai long; long spindle-form; 

 posterior end sharply pointed; flagellum short; spiral striation on 

 pellicle very delicate; paramylon bodies several, rod-form; nucleus 

 central; stigma distinct; numerous disc-like chromatophores; slug- 

 gish. 



E. spirogyra E. (Figs. 24, c; 101, d). 80-125m by 10-20^; cylin- 

 drical; with spiral striae, consisting of small knobs; numerous disc- 



