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A TEXTBOOK OF THEORETICAL BOTANY 



spherical cells are formed all enclosed in the original membrane. Eventually 

 this breaks and the individuals separate and grow into normal euglenoid 



r FLAGELLUM 



CYTOSTOME 



PLASTID 



NUCLEUS 



SPHINCTER 



CANAL 



STIGMA 



RESERVOIR 



BASE OF 

 FLAGELLUM 



BASAL 

 GRANULE 



Fig. 29. — A, Euglena deses. Diagram of the entire cell. {After Klehs.) B, Euglena 

 ehrenbergii. Details of the anterior end of the cell. {After Hamburger.) 



cells. In dividing while at re&t Euglena differs from the majority of the other 

 Flagellates, and shows an approach to the true Algae. 



Cysts with thick walls are frequently found ; they are generally spherical 

 and the walls are striated. Very often such cysts are red in colour due to a 

 red pigment, haematochrome, in the cells. Such encystment may be only 

 temporary, and the individual may retain its flagellum. If, however, the 

 process is employed to tide the organism over a longer period of unfavourable 

 conditions the enclosed cell may retract its flagellum. 



Except in one doubtful case sexual reproduction is unknown in any 

 species oi Euglena. 



