188 Macfarlane— Current Problems 
ability of parts may be largely or wholly reversed during 
division, as do the later studies of Miss Sargant, Farmer, 
Wager and Dixon. 
Miss Huie’s experiments on the feeding of Drosera leaves 
prove that an intimate relation exists between the nucleus 
and nucleolus, and that reciprocal chemical changes are con- 
stantly proceeding in them. While differential stains may 
often aid us in the demonstration of structural details, they 
may prove fallacious guides in the zxterpretation of morpho- 
logical and micro-chemical relations. 
The nuclear membrane is now so universally conceded to be 
a morphological feature of the resting nucleus that the appli- 
cation of a definite name is appropriate. Apart from the 
study of living cells, carefully fixed material alone presents 
the natural appearances. Alike in living and stained cells it 
shows striking resemblances to the threads of the nuclear 
network internally, and to the radiating kinoplasmic threads 
which traverse the proptoplasm externally. In some plants it 
is evidently continuous with the latter. But where imperfect 
fixation has been effected, the membrane often resolves itself 
into a system of threads and knots, in no way different from 
the nuclear network. This may be even characteristic of 
living cells, as we shall have occasion to mention later, and 
has caused Wisselingh to describe the membrane as made up 
of ‘small bodies, lumps and granules.” Its behavior 
when fresh cells of Spirogyra nitida are simultaneously 
swollen up and stained by 50 per cent alcoholic eosin is 
instructive. As osmosis proceeds, the radiating strands 
from the nucleus snap suddenly along one side, the 
enveloping protoplasmic mantle of the nucleus then immedi- 
ately expands on that side, while the nuclear membrane 
remains as a puckered but continuous envelope. But it is 
during the dividing state of the cell that we can learn mostas 
to its morphology. In Spirogyra nitida, during the prophase 
