1 (i Olivo, ^litotit" division ol' llic iinclei of tlu« CVanCiiliyfeae. 



bo eonfined to tlic p('n])heial clensor portion, and only in tlie 

 central colorless (or at times sliglitly «ri-eeni.sh) rogion ^vill be 

 observed tlie grannies, now distinctly colorless, ^vlli(•h \ve liad 

 previously remarked in side view. The color is in this instance 

 not caiised by minute green grannies, but it appears ratlier to 

 be due to a nniformly diffused substance, eonfined to tlie peri- 

 plieral, sometimes distinctly fibrons, region wliicli Fischer calls 

 the chromatophore. Such a Chromat o])hore probably iinds its 

 parallel in many of the lower algae, in llotJ/rix, for example, in 

 Hydro(Vuiyo)i. and others. 



The granulation in Gloeocapsa is clearly visible, botli in the 

 living condition as well as in the cell treated with Chloroform 

 water. Fig. 36 repi'esents a cell so treated, with much of the 

 ])hycocyanin still eonfined in the space between the shrunken 

 cell and the thick, gelatinous membrane. In this condition, it 

 is impossible to say whether the granules Avhich we can see so 

 clearly are green or not. But when the Chloroform water is 

 allowed to act for several days, sometimes the wall of the dead 

 cell is broken down (iig. 35), leaving imbedded in the firm ge- 

 latinous membrane nothing but the multitude of colorless gra- 

 nules. These granules, which Schmitz called slime globules, 

 *are probably, therefore, merely granules of reserve food matter, 

 although the writer is not yet prepared to say that they are 

 cyanophycin. 



The central body. 



Schmitz was the fii*st, in 1879, to call the central body in 

 the cell of Gloeocapsa a nucleus. The very next year, howover, 

 (80) he came to the conclusion, after further study, that the 

 minute granules of this central portion were microsomes and 

 that they did not represent a nucleus. This opinion he repeated 

 tlu'ee years later (83), after studying many Cyanophyceac ^ and 

 he made the general Statement that these plants possessed cells 

 without nuclei. Zacharias (87 j after his hrst studies on Toly- 

 jjofhrix and Oscülatoria, also held the opinion that the central 

 body contains chromatin and that it represents a nucleus, but, 

 later (90), he saw reasons to modify his views and concluded 

 that. although the body in question contains chromatin, it is 

 probably not a nucleus. To this opinion, Zacharias evidently 

 still clings. 



Macallum (99) also holds a similar view, that, although he 

 has demonstrated that chromatin is present in the cells of the 

 Cyanophyceac and the Barferia, they are nevertheless non-nu- 

 cleated organisms. On the contrary, Lawson (03) contends that 

 the chromatin granules represent the nucleus, „since every highly 

 organized nucleus passes through a stage in its development 

 when it consists of nothing but chromatin." 



Others who believe that the central body is not a nucleus 

 are Marx (92), who, indeed, could see a central body „nur äußerst 

 selten", Palla (93), Chodat (94), Stockmayer (94), Fischer 



