SPECIAL MORPHOLOGY OF THE PROTOZOAN NUCLEUS 



('93) in Achromatium. A careful distinction should be made be- 

 tween these types. In Loxophyllum (Balbiani, '60), Urostyla (Bergh, 

 '89), and Tetramitus (Calkins, '98), the chromatin granules come 

 together and form a single nucleus prior to division. 



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Fig. 134. Types of nuclei. [A. Calcituba polymorpha Roboz, from SCHAUDINN. B. Colpidium 

 colpoda, from a preparation. C. Euglena viridis Ehr. from a preparation. D. Tetramitus ckilomo- 

 nas, n. sp. E. Npctiluca miliaris Sur., from a preparation.] 



A single karyosome (A} becomes vesicular, and ultimately gives rise to several daughter-karyo- 

 somes (so-called "fragmentation" Schaudinn). Several karyosomes in Noctiluca (J5) hold the 

 chromatin, the rest of the nucleus is filled with " achromatic " granules. In Tetramitus chilomonas 

 (D) the chromatin is scattered throughout the cell ; the lighter-colored body in the centre of the 

 cell is the homologue of the deeply stained central body in Euglena (C). 



