in the Hymenomycetes. 507 
basidium, and the nuclear membrane soon disappears at these 
points, which may be regarded as the apices of the nuclei. 
The nuclear network now becomes transformed into a number 
of deeply stained red chromatin-granules, which accumulate 
at the apex of each nucleus, in contact with the cytoplasm 
(Figs. 20 and 21). The nucleoli meanwhile become much 
smaller in size and lose their capacity for taking up the red 
stain. The rest of the nuclear membrane begins to disappear, 
and the protoplasm around the two nuclei, at this stage, again 
stains more deeply than before, probably owing to the escape 
of the nuclear sap with the dissolved nucleolar substance. 
A nuclear spindle now appears, in contact with each group 
of chromatin-granules. In favourable specimens they can be 
very distinctly seen (Fig. 22), and at each pole of the spindle 
a deeply stained granule (centrosome ?) is visible. The latter 
are well seen in Fig. 22, in which the two drawings represent 
the same basidium at two different levels to show the dividing 
daughter-nuclei. The very much reduced nucleoli are still 
visible. 
The division of the two groups of chromatin-granules 
now takes place. The two daughter-groups produced in each 
case, separate along lines which are parallel to each other, 
in a transverse plane, near the apex of the basidium. After 
traversing an angle of about 45 0 they stop and are then in 
close contact with the wall of the latter. At this stage, 
a superficial glance at a transverse section of a basidium 
shows these separated groups as small deeply stained masses, 
about equidistant from one another, quite close to the wall 
of the basidium, and between them the remains of the two 
spindle-figures (Fig. 23). The faintly stained remains of the 
nucleoli can still be seen and, on focussing a little deeper, the 
faintly stained, indistinct portions of the two old nuclear 
membranes. 
A. muscarius. The formation of the equatorial plates in 
the daughter-nuclei of this species differs slightly from that of 
A. stercorarius. The outline of each nucleus becomes very 
irregular, and as the chromatic elements are formed they take 
