the Yeast Plant . 
59 
and in some cases was partially separated from it. The outline of the 
nucleolus in these cases remained intact, showing conclusively that the 
granules are not contained within it, but are closely associated with its 
surface (Figs. 81-93). 
In perfectly normal cells, in the resting condition, and in the early 
stages of fermentation, the peripheral deeply stainable chromatin is present 
in the form of a single large granule situated on one side of the nucleolus 
(Figs. 53, 54, 106). As fermentation proceeds it increases in size, forming 
a cap surmounting the nucleolus (Figs. 67, 72, 116), and, under favourable 
conditions during the period of highest fermentative activity, it may extend 
over the greater part of the surface of the nucleolus. In preparations 
of such yeast stained with a general stain such as Mayer’s haemalum, 
no indication of this encrustation is obtained, but the nucleolus appears 
to be very large, and doubtless the marked variation in the quantity 
of chromatin present on the surface of the nucleolus accounts to some 
extent for the variation in the size of this body, which has been noted 
by Guilliermond and Macallum. 
New centres for the formation of the deeply stainable chromatin may 
occur on the periphery of the nucleolus, giving rise to some peculiar 
appearances that might be mistaken sometimes for the reticulate structure 
of a nucleus possessing a well-marked nucleolus (Fig. 73), sometimes for 
mitotic figures (Figs. 66, 69, 71) ; and Feinberg (’ 02 ) is possibly referring 
to one of these appearances when he says that ‘ the nucleolus sometimes 
shows a looser structure in which the separate pieces can be distinguished ’ 
(Figs. 56, 68, 70, 75, etc.). It is not uncommon for a new centre to arise 
at the side of the nucleus opposite to the original patch, bringing about 
an appearance which strongly resembles the anaphase of a typical mitotic 
division (Figs. 55, 60), and has evidently been mistaken for such by 
Swellengrebel (’ 05 ) and Fuhrmann (’ 06 ). The amount of chromatin 
present is at a maximum between thirty and forty-eight hours after the 
commencement of fermentation. After forty-eight hours it diminishes, 
first disappearing in the neighbourhood of the vacuole and gradually 
decreasing until there only remains a granule similar to that present in the 
early stages of fermentation. 
In some cells the single granule is replaced by smaller granules, which 
may be few in number and comparatively large (Fig. 56), or numerous and 
more or less minute, when they may occur in a group, a double row, or 
a single row which may extend half-way round the nucleolus (Figs. 61-4, 
70, 74). Sometimes we get a nucleolus completely surrounded by minute 
granules (Wager (’ 98 ), Fig. 4). Occasionally, in surface view, they appear 
in the form of a band across the nucleolus (Figs. 64, 71). Sometimes we 
get one large granule and a number of smaller ones (Fig. 70). 
There can be little doubt that these granules correspond to the 
