Cytology and Movements of the Cyanophycee. 289 
controlling centre of cell activity (86). What, then, if they 
have no nucleus, can act as the governing agent in these 
lower plants? Strasburger’s experiments seem to prove 
that proteids are formed only by the nucleus. If the Cyano- 
phycez have no nucleus, what, we may say, forms the pro- 
teids which are demonstrable in their cell contents? These 
considerations would lead, a priori, to the conviction that 
there must be a nucleus present in these so-called non- 
nucleated organisms, or at least something that performs 
the functions of one, if we are to accept the great bulk of 
work done on many lines by cytologists. Whether this con- 
trolling structure in the Cyanophyceze should be called a 
nucleus, or by some other name, the organ functions as such, 
and the difference is, evidently, a matter of the definition 
of nucleus, and therefore a mere matter of words. The 
localization of this controlling influence seems to be the 
problem. If it should be found that here we have cells 
exhibiting all of the properties of nutrition, growth, repro- 
duction, heredity, etc., but devoid of chromatin in any form, 
it would seem to weaken the conception of the nucleus above 
referred to. But the investigations reported here show that 
the Cyanophycez are in no sense an exception to the scheme 
of evolution, but in reality one of the earliest steps in the 
phylogeny of the nucleus. 
The Chromatophore. 
Fischer was able, with hydrofluoric acid, to digest away 
all of the protoplast except a hollow, barrel-shaped struc- 
ture which contained the coloring matter. This he termed 
the chromatophore. He therefore considered the Cyano- 
phycez to be without nuclei, but to have a color-bearing 
organ. Buiitschli, on the other hand, was able to digest only 
the outer portion, while the central body was undigested, 
and he thus drew the conclusion that nucleus and chroma- 
tophore were both present. 
