1898-99. ] ON THE CYTOLOGY OF NON-NUCLEATED ORGANISMS. 475 
contains a collection of granules of chromatin which stain differently 
from the substance in which they are held, and more deeply. Not un- 
frequently there may be several masses sometimes completely separate 
from each other, in other cases connected by narrow strands of the same 
substance. In some cells also the granules which Mitrophanow terms 
“nucleolar” are uniformly distributed throughout the cytoplasm of the 
cell. In such no nucleus is visible. In Ophzdomonas jenenszs the central 
elongated mass reminds one of the central body of Biitschli, the peri- 
pheral cytoplasm corresponding to the peripheral layer of that author. 
This mass may appear divided into a number of smaller vesiculated 
irregular clumps of substance. In Aeggzatoa the masses are always 
spherical, and, to judge from Mitrophanow’s figures, homogeneous in 
composition. Several of these may be present in the cell, though as a 
rule there are not more than two large ones. 
Mitrophanow’s terminology is very obscure. He applies the term 
nucleus to the large elongated, centrally placed mass and the term 
nucleoli to the granules which it may contain, or to those which may be 
distributed throughout the cytoplasm. In the case of Beggzatoa the 
granules found are loosely described by him as nncleoli. He has 
advanced nothing, except, perhaps, facts in regard to staining capacity, 
which justify the application of the term nucleus to these structures. 
In neither Chromatzum nor Beggzatoa could Fischer find a differentia- 
tion of the cytoplasm into central body and peripheral layer, such as 
Biitschli describes. In Chromatium there may at times be a condensation 
of the cytoplasm in the centre of the cell, brought about by the arrange- 
ment and disposition of the sulphur droplets which it contains, There 
may be in each cell a number of spherical grains of a deeply stainable 
substance which Fischer hesitates to regard as chromatin, for after the 
use of some chromatin-fixing reagents the granules formed of it are not 
to be seen. In Seggzatoa Delafield’s hematoxylin brings out the pres- 
ence in each cell of “red” granules such as Biitschli describes. In 
subsequent treatment of these preparations with safranin the central 
portions of the cells stain a little more deeply than their periphery, but 
_this is due to condensation of the cytoplasm through the disposition of 
the sulphur granules. In cells free from sulphur this result is not 
obtained. There is no nucleus and the granules cannot definitely be 
regarded as formed of chromatin. 
The writer' pointed out that the “masked” iron compound is dis- 
1 ‘‘On the Distribution of Assimilated Iron Compounds, other than Hemoglobin and Hzematins, in 
Animal and Vegetable Cells,” Quart. Journ. Micro. Sci., Vol. XXXVIII, p. 258. 
