Cytology and Movements of the Cyanophycee. 287 
it would not fall far short of the restricted conception of a 
nucleus. It has a much more definite form than the diffused 
nucleus of the Infusorian Trachelocerca, as described by 
Gruber (29), and the ground substance of the central body 
quite represents the more fluid parts of the nucleus, while 
Hieronymus, Strasburger and others have been able to find 
a definite nuclear membrane. The second, and more com- 
prehensive definition of a nucleus, is certainly fulfilled by 
the central body of the Cyanophycez. There is as much 
evidence for the chromatin of the Cyanophycez being the 
hereditary material of these organisms, as there is to con- 
sider it such in the higher plants. Moreover, that the con- 
structive metabolism is governed by the central body is 
evidenced by the fact that plants which have been cultivated 
in solutions which starve the chromatin, are never healthy 
and strong, the cyanophycin grains often disappearing. The 
definite threads of kinoplasm which radiate from the central 
body and pass into the ciliary processes, suggest evidence 
that the movements are directed by the same organ, while its 
activities in the formation of spores and in division show 
that it has much to do with reproduction. The argument 
that the central body has no stable morphology has been 
refuted by Biitschli (9), who showed that it is no more 
variable than true nuclei. Strasburger also mentions the 
finding of cells, no longer capable of division, which might 
have several nuclei, the result of fragmentation. The cen- 
tral body of the bacteria was studied by Nadson, who con- 
cluded that their nucleus was diffused throughout the whole 
of the cytoplasm, very much as the present investigation has 
shown the coloring matter of the Cyanophycez to be. This 
would mean the same intermingling of the functions of 
cytoplasm and nucleus as exists between the functions of 
cytoplasm and chromatophore in the Cyanophycez. This 
form of protoplast Nadson termed an “Archiplast.” He 
often found scattered granules of chromatin in the Archi- 
plast. Biitschli considered the bacteria to consist of a cen- 
