Cytology and Movements of the Cyanophycee. 249 
a colorless foundation-mass. In 1900 Zacharias again pub- 
lished the results of an investigation of much moment. In 
it he discussed at some length the staining theories of 
Fischer in a manner that brought out many interesting 
points. In fact Zacharias has published several (92, 93) 
very able articles on methods of cytological investigation 
which have been of great value in the present inquiry. His 
conclusions were that while there were restrictions to be 
held in mind, still it was quite admissible to use staining 
reactions in determining the cell and nuclear constituents. 
In this work, Zacharias, in discussing at great length the cell 
contents of the Cyanophycez, concluded that “from the 
present state of our knowledge we can say in regard to the 
arrangement of the colored and colorless contents of the 
cell, that a colorless central body is surrounded by a colored 
plasma. The latter may be lacking under certain condi- 
tions,” but as there was no bounding membrane, he would 
not call the colored portion a chromatophore. The central 
body was a very irregular, structureless and compact mass, 
enclosing larger or smaller colorless spaces. Its contents 
showed great varieties of condition, even in the same species. 
He said, “As many different species of Lyngbya as are in 
the palm house at Hamburg, each one showed a different 
arrangement in the cell rows.”” The same species also dif- 
fered at different times of the year. The granular constitu- 
ents he considered to be of two kinds, the cyanophycin 
granules in the peripheral plasma, and the colorless central 
granules embedded in the periphery of the central body, 
which corresponded to Palla’s slime balls, though he did not 
use that term on account of the different meanings given to 
it by different authors. He considered it quite possible 
that his “central granules” were composed of chromatin 
though he was unable to demonstrate it to his satisfaction. 
When treated with 28 per cent. hydrochloric acid they had 
the appearance of hollow balls. They occurred most abun- 
dantly in the spores and not at all in the heterocysts. It was 
