294 PROTOZOOLOGY 



Family 1 Euglenidae Stein 



Body plastic ("euglenoid"), but, as a rule, more or less spindle- 

 form during locomotion. The flagellum arises from a blepharoplast 

 located in the cytoplasm at the posterior margin of the reservoir. 

 Between the blepharoplast and the "cytostome," the flagellum shows 

 a swelling which appears to be photosensitive (Mast, 1938). Many 

 observers consider that the basal portion of the flagellum is bifur- 

 cated and ends in two blepharoplasts, but Hollande (1942), Prings- 

 heim (1948) and others, hold that in addition to a long flagellum 

 arising from a blepharoplast, there is present a short flagellum which 

 does not extend beyond the neck of the reservoir and often adheres 

 to the long flagellum, producing the appearance of bifurcation. Cul- 

 ture and physiology (Mainx, 1928); cytology (Giinther, 1928; Hol- 

 lande, 1942). 



Genus Euglena Ehrenberg. Short or elongated spindle, cylindrical, 

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

 striae; some with a thin pellicle highly plastic; 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; 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 reproduction by longitudinal 

 fission; sexual reproduction reported in Euglena sanguined ; 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 encysted stages may produce con- 

 spicuous green spots on the bottom of pond or pool; in fresh water. 

 Numerous species (Pascher, 1925; Johnson, 1944; Gojdics, 1953). 



E. pisciformis Klebs (Fig. 118, a). 20-35/* by 5-10/*; spindle-form 

 with bluntly pointed anterior and sharply attenuated posterior end; 

 slightly plastic; a body-length flagellum, active; 2-3 chromato- 

 phores; division into two or four individuals in encysted stage 

 (Johnson, 1944). 



E. viridis Ehrenberg (Fig. 118, 6). 40-65/* by 14-20/*; anterior end 

 rounded, posterior end pointed; fusiform during locomotion; highly 

 plastic when stationary; flagellum as long as the body; pellicle ob- 

 liquely striated; chromatophores more or less bandform, radially 

 arranged; nucleus posterior; nutrition holophytic, but also saprozoic. 

 Multiplication in thin-walled cysts (Johnson). 



E. acus E. (Fig. 118, c). 50-175/* by 8-18/*; body long spindle or 



