Cytology and Movements of the Cyanophycee. 295 
tation of the other constituents, and it may be well to men- 
tion some of these. By micro-chemical methods it is found 
that glycogen occurs constantly in the cells of the Cyano- 
phycez as claimed by Errera (24), and is probably the 
form in which much of the food is found. The granules 
and vesicles of the central body give evident reactions for 
iron and phosphorus. The vesicles are not dissolved by 
gastric digestion, but take a strong yellowish hue, like the 
nuclei of Spirogyra filaments when placed in the same fluids 
with the Cyanophyceze. Tryptic digestion also fails to 
dissolve the central body, as does 10 per cent. potassium 
hydrate solution. The central body gives faint tests for 
plastin. Neither bichloride of potassium nor iron reveals 
tannin. In cells that have ceased to multiply, osmic acid 
reveals oil droplets in the outer protoplasmic zone. It will 
be seen, therefore, that these and other micro-chemical 
results that have been mentioned above, give strong con- 
firmatory proofs of the conclusions here drawn. 
(3) MorpHoLocy oF THE DivipiInG CELL. 
The resting stage of the cell differs greatly from the 
dividing condition of the same cell. In the former it has 
been shown that the chromatin is aggregated into a number 
of hollow vesicles. As the cell begins to divide, these vesi- 
cles give up their chromatin which becomes very diffuse 
throughout the central body (Fig. 6), gradually forming 
into a more or less loose network (Figs. 2, 16, 67). This 
network is composed of faintly staining threads along 
which, and especially at the points of juncture of one thread 
with another, small chromatin granules are situated (Figs. 
2, 16). These chromatin granules multiply by divisions 
that are transverse to the axis of the thread (Fig. 23). This 
division is not the longitudinal splitting found in the 
spiremes of higher cells for the purpose of equally dividing 
the probable hereditary material, but is apparently merely 
