1898-99. | ON THE CYTOLOGY OF NON-NUCLEATED ORGANISMS, 487 
two or more smaller ones which in turn are replaced by many others 
and, as a consequence, the protoplasm acquires the foam structure of 
Bitschli. The nuclear body moves towards the centre, the protoplasm 
condenses about it, and on the periphery of this condensed zone deeply 
stainable granules collect. The nuclear body now appears to take up 
from the surrounding cytoplasm all the stainable material, and to 
deposit it in its centre as a granular mass. The division of the nuclear 
body occurs as Wager describes it in his earlier paper. 
In regard to the nature of the nuclear apparatus, Wager regards it as. 
a simple form of a nucleus, although he admits the possibility of it being 
either a primitive structure representing an early stage in the organo- 
geny of the nucleus, or a degenerated form of nucleus. The division 
of the nuclear body, he thinks, may be regarded as a case of direct 
division, but, in his opinion, it may also be a very simple case of kary- 
okinesis. 
In my own studies on the distribution of assimilated compounds of 
iron, I pointed out that, in S. cerevesee and S. Ludwwigiz, chromatin is to 
be found distributed throughout the cytoplasm of the cells and, some- 
times, also in the latter in the form of granules ; but, in S. Ludwezgz, it 
may be found chiefly at the periphery of each large vesicle, when only a 
few large vesicles are present in the cell. In this form also there is a 
substance constituting corpuscles of a nucleolar character, the nuclei of 
Moeller, which stains with eosin, and gives a marked reaction for iron, 
but differs from chromatin in remaining unstained after treatment with 
hematoxylin. My conclusion was that there is no nucleus, although 
such an organ may occur in other stages of this organism. In a later 
contribution embodying the results of observations made to determine 
the distribution of organic phosphorus in animal and vegetable cells, I 
pointed out that in the yeast cell the phosphorus-holding substance, or 
nucleo-proteid, although sometimes in the form of granules or spherules 
which have been taken for nuclei, is frequently dissolved in the cyto- 
plasm. 
It will be seen from this abstract of the more recent literature on the 
yeast cell, that there are some discrepancies in the views of various 
investigators of the subject. An agreement is indeed found as regards 
the division of the nuclear body or nucleolus, but not as to the manner 
of this division. The most radical difference, perhaps, exists between 
Wager, on the one hand, and Janssens and Leblanc on the other, as to 
what constitutes the nucleus, and as to its structure apart from the 
nuclear body or nucleolus. 
