Cytology and Movements of the Cyanophycee. 245 
cause the filamentous plants to assume the forms of short 
rods and coccus-shaped cells, thus proving that a much 
closer connection existed between the Cyanophycez and the 
Bacteria than had been hitherto supposed, even by Cohn or 
Sachs (66) who were the first to place the two groups 
together in the Schizophyta. Several forms as _ here 
described are doubtless produced when a filamentous alga 
breaks down in death, but it would, however, scarcely seem 
proper to consider as a part of the life-history of a plant, a 
phenomenon caused by an evident pathological condition. 
Methods quite similar to those used by Zopf were employed 
in the present investigation for the purpose of causing spore 
formation, with the result that the filaments would break 
dcwn after forming spores. These may be the unicellular 
forms spoken of by Zopf. Concerning the structure of the 
cell, he says little, except to assert that a nucleus was present 
(96) in Phragmonema, but he was somewhat uncertain as 
to whether it should not rather be termed a vacuole. 
According to Gomont (33) the cells and hormogonia of 
the Homocystez always possessed a delicate laminated mem- 
brane, which in the later formed and younger cells consisted 
of a substance closely allied to cellulose, but in the older 
cells it resisted all such reagents and he considered it to be 
a substance between the cuticle of the higher plants and 
fungus cellulose. The sheath of the Homocysteze (31) 
ranged between hyaline and gelatinous, becoming hyaline 
for protection when exposed to light and air. It was dis- 
tinctly laminated. The protoplasm was colored uniformly 
a blue-green, but had small granules of two kinds, one 
small, irregular in outline, refringent and collected usually 
at the ends of the cells, the other about I w to 2 p 
in diameter and supposed by Zacharias (89) to be composed 
of a hydrocarbon. The former were most abundant in the 
older cells, being scarcely shown in the growing tip where 
division is most abundant, and were entirely lacking in 
newly formed cells. Both kinds of granules could exist in 
