SPECIAL MORPHOLOGY OF THE PROTOZOAN NUCLEUS 



251 



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

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

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

 together and form a single nucleus prior to division. 



Pig. 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 chilomo- 

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



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

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



