Cytology and Movements of the Cyanophycee. 325 
(9) SumMMaRyY OF RESULTs. 
1. The central body of the Cyanophyceze is composed of 
chromatin and is a true cell nucleus. 
2. This nucleus divides by one of two methods, both of 
which start upon the karyokinetic history, one going no 
further than the net-spireme stage where it constricts itself 
into halves, while the other continues further and forms a 
rudimentary spindle with rudimentary chromosomes upon 
linin threads. 
3. In both forms of division, the nucleus divides itself, 
not being strangled into two parts by the ingrowing parti- 
tion wall. 
4. The chromatin is arranged on the spireme thread in 
granules which multiply in number by transverse divisions. 
5. There is no longitudinal splitting of the chromosomes 
or of the spireme, and in the division of the cell by the 
method first mentioned above, the two portions of the 
nucleus are not necessarily equal. 
6. The chromatin is aggregated in hollow vesicles in the 
resting cell. These vesicles give out their chromatin to the 
net-spireme very much like the nucleoli of higher plants, 
and they may represent it. They are imbedded in a granular 
ground substance. 
7. The outer zone of the protoplast is divided into two 
portions, a thin colorless ectoplasm lining the cell wall, and 
the thicker layer between it and the central body. This 
latter portion contains the pigments which are dissolved in 
it, and is rightfully termed the chromatophore. 
8. The cyanophycin granules and slime balls are probably 
food products. They are located in the chromatophore. 
9g. The movements of Oscillaria, Cylindrospermum and 
the other forms of the Cyanophycee which exhibit motion, 
are caused by delicate protoplasmic cilia distributed along 
the sides of the trichome. 
10. Finger-like processes of the ground mass of the 
