THE NUCLEUS 



39 



it shows the same staining reactions as chromatin, or may be double, 

 consisting of an outer achromatic and an inner chromatic layer. Ac- 

 cording to Reinke, it consists of oxychromatin-granules like those of 

 the linin-network. 



Interesting questions are raised by a comparison of these facts 

 with the conditions observed in some of the lowest organisms, such 

 as the flagellates and lower rhizopods among animals and the 



A 



D 



«, • / 



B 









H 



O 



F 



% 



'%) 



7 



E 



or distrib 



Fig i6.- Forms of Cyanophyce^, Bacteria, and Flagellates showing the so-called scattered 



distributed nuclei. [.4-C BuTSCHLi; Z?-/^ Schewiakoff; G-y. Calkin^.] 



A. Oscillaria. B. Chromafmrn, C. Bacterium lineola. D. Achrowatiuw. E. The same m 



division. /; Fission of the granules. G. 7l'//-</w////.^ with central sphereandscatteredgninu.es. 



H. Aggregation of the granules. /. Division of the sphere. J. Fission of the cell. 



Cyanophyce^ and Bacteria among plants. In many ol these forms 

 (Fig. i6) no distinct nucleus can be demonstrated, the cell consistmg 

 of a mass of protoplasm in which are scattered numerous deeply 

 staining granules. Many of these granules stam mtensely with 

 hematoxylin and other " nuclear" dyes; like chromatm, they resist 

 the action of peptic digestion, and in at least one case (the bacterium- 

 like AckromatiHm, according to Schewiakoff, '93) they have the power 

 of division like the chromatin-granules of higher forms. For these 



