ISO 



BIOLOGY OF THE PROTOZOA 



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Fig. 89. — Didinium nasidum O. F. M. capturing and swallowing Paramecium 

 caudatum. 1 to 6, Successive stages in the ingestion of Paramecium; 7, section of 

 conjugating form of Didinium with spindle-form gastric vacuoles (?), and two micro- 

 nuclei in mitosis; 8, section of Didinium just prior to encystment. The seizing organ 

 with zone of trichocysts is protruded from the mouth; and rhizoplasts run from the 

 membranulse (motile organs) deeply into the cell. (After Calkins.) 



