PLATE 23. 



Fig. 12. Symploca Muscorum. Longitudinal section. Living material 

 stained with aqueous methylene blue. The cytoplasm has a greenish 

 blue color, the chromatin a deep blue; the granules are red. a is a 

 cell just beginning to divide; b, the cell-wall has grown into the chro- 

 matin, which is just beginning to separate; c, division almost com- 

 pleted. 



Fig. 13. Symploca Muscorum. Longitudinal section. K. I. Ehr. Haem. 

 30 minutes, counterstained with wasserblau 5 minutes, and washed 

 out with acidulated alcohol, then with Ehr. Haem. again. Wasser- 

 blau reveals the j8 granules in the nucleus and in the cytoplasm. 



Fig. 14. Oscillatoria margaritifera. Cross section. K. I. Aqueous thionin 

 washed in acidulated alcohol, counterstained with wasserblau and 

 again washed with acidulated alcohol. The a granules are stained 

 red and the /3 granules are stained blue. They are both here repre- 

 sented in the same plane, but in reality the red ones are in a plane 

 below the blue ones. 



Fig. 15. Same species and view as Fig. 14. K. I. Wasserblau washed in 

 acidulated alcohol. Shows only f3 granules. 



Fig. 16. Same species and view as Figs. 14 and 15. K. I. Aqueous thionin 

 washed in acidulated alcohol. 



Fig. 17. Oscillatoria splendida. Longitudinal section. Living material 

 Ehr. Haem. 5 minutes, counterstained with wasserblau 15 seconds. 

 Ehr. Haem. was not on long enough to stain the a granules, nor was 

 the wasserblau on long enough to stain the /3 granules. 



[290] 



