Reproduction and Life-Cycles 57 



tion. Duplication of blepharoplasts, apparently by division, is character- 

 istic of fission in the flagellate stage. The behavior of blepharoplasts in 

 non-flagellated stages of Phytomastigophorea is mostly unknown, al- 

 though they persist as division-centers in Eudorina illinoisiensis (117). 

 The fate of other cytoplasmic structures in fission seems to be variable. 



Fig. 2. 2. A-G. Fission and regeneration of missing portions of tfie body 

 and theca in Ceratium hiruncUnella; diagrammatic (after Entz). H. Late fis- 

 sion in Oxyrrhis mariym; nuclei and fiagella indicated diagrammatical!) : 

 xHOO (after Hall). I. Heteronema acus; division of body starting at anterior 

 end; endosomes shown, chromosomes omitted; xl395 (after Loefer). J. Late 

 fission in Tritrichomonas augusta; xl305 (after Kofoid and Swezy). K. Fission 

 in palmella stage of Haematococcus pluvialis; xl815 (after Elliott). L. Early 

 fission in a lophomonad flagellate; nucleus divided and new sets of organelles 

 developing; old organelles degenerating; diagrammatic; xl25 (after Kirby). 



