Cytology and Movements of the Cyanophycee. 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 haematoxylin, 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 hzema- 
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. Biitschli and Nadson 
were unable to stain their reserve granules with hematoxy- 
lin, but found that eosin gave them a deep red tint. Cyano- 
phycin granules are not dissolved by dilute hydrochloric 
