6 o Wager and Peniston.—Cytological Observations on 
chromatin elements described by Guilliermond (’ 02 ) as occurring in the 
nuclear hyaloplasm in favourable cases, pressed close to the membrane 
of the nucleus (nucleolus), or in the form of two or three large masses 
or of small filaments radiating from the centre. In cells which have been 
living for some time under bad nutritive conditions, it is found that in 
practically every case the dense granular mass is replaced by more or less 
numerous small granules, whereas in cells from healthy cultures this 
condition is only occasionally met with. It is also found that such a con¬ 
dition can be induced by simply placing the yeast under adverse nutritive 
conditions, either in a very dilute sugar solution, or on pieces of carrot, 
or in water. 
In cells which have been living for a short time—about two hours— 
under these conditions, four or five granules are present at the periphery 
of the nucleolus. In twelve hours the granules are more numerous, but 
smaller and farther apart. Still later the nucleoli in most of the cells 
are wholly or partially surrounded by minute granules more or less evenly 
distributed over the surface of the nucleolus. But, although they in¬ 
crease in number, they become individually smaller, and there seems to 
be a gradual diminution in the actual quantity of stainable substance. 
This takes place so slowly that it is only perceptible when the cells are 
examined at long intervals. 
The general appearance of the yeast cell under these conditions, as 
seen in preparations stained according to Heidenhain’s methods, throws 
some light on the observations of Swellengrebel and Fuhrmann. The 
cytoplasm is deeply stained, the nucleolus is almost invisible and is often 
somewhat paler than the cytoplasm (Figs. 51, 57). The vacuole is small 
and is frequently no larger than the nucleolus ; it contains no stainable 
granules and, as in the case of the nucleolus, is visible only as a faintly 
outlined somewhat paler area in the cytoplasm. The only part of the cell 
that remains strongly differentiated is the deeply stainable chromatin at the 
periphery of the nucleolus (Figs. 56-8, 61-76). When only four to six 
granules are present, they are very conspicuous, and are commonly situated 
between the nucleolus and the vacuole, in which position they look very 
much like chromosomes at the equator of a spindle-shaped figure (Figs. 58, 
61), the faintly outlined nucleolus and vacuole corresponding to the halves 
of the spindle. 
It is significant that the only stages in this mitotic division that 
Swellengrebel (’ 05 ) appears to have observed clearly should be the meta¬ 
phase and disaster stages, and that appearances strongly resembling these 
should be of frequent occurrence in the yeast cell. 
We have examined a large number of cells in all stages and under all 
conditions of development, and we feel convinced that all these various 
appearances which are so strongly suggestive of mitotic figures are accidental 
