Cytology and Movements of the Cyanophycece. 293 



which have been growing under conditions where abundant 

 nutrition can be obtained, and diminishing in number as 

 the nutrition of the plant decreases. In dividing cells they 

 are least in evidence. They are irregular in form and size, 

 being quite small and round to sub-angular in shape. They 

 appear thus to be either reserve or assimilation food prod- 

 ucts, probably the former. They are faintly stainable with 

 Delafield's hsematoxylin, taking a blue tinge. When treated 

 with weak hydrochloric acid (4 per cent.), or i per cent, 

 sulphuric acid, they disappear entirely. Chloral hydrate 

 solution also seems to dissolve them. These are probably 

 the same granules that were termed "reserve granules" by 

 Biitschli and Nadson, and what Palla and Borzi called 

 cyanophycin. Hieronymus considered these cyanophycin 

 granules to be composed of chromatin, while Zukal thought 

 them to represent the nucleoli. Deinega called all granules 

 an isomer of starch. They are much fewer in number in the 

 cells of Nostoc enclosed in the thallus of Collema, where 

 their symbiotic relations probably cause them to give up 

 their surplus or reserve food to the fungus. Slime balls 

 rarely occur in these cells. A second form of granule found 

 in the cytoplasmic layer is what Schmitz termed "schleim- 

 kugeln." They are larger than the cyanophycin granules, 

 and appear to be composed of a mucous substance of greater 

 or less consistency, often verging upon the solid state. 

 Chemically, they give the reactions of carbohydrate sub- 

 stances. When treated with 6 per cent, solution of potas- 

 sium hydrate they often swell, similarly to the paramylum 

 grains of Euglena. They stain blue with Delafield's hsema- 

 toxylin and red with eosin. Their apparent carbohydrate 

 nature somewhat militates against their being identical with 

 the reserve granules of Biitschli, though it allies them with 

 the "schleimkugeln" of Schmitz. Butschli and Nadson 

 were unable to stain their reserve granules with heematoxy- 

 lin, but found that eosin gave them a deep red tint. Cyano- 

 phycin granules are not dissolved by dilute hydrochloric 



