Centi'ospheres in Fungi . 325 
then an archoplasmic body, which answers very nearly to the 
description of these structures in A . galericulatus. 
However irregularly these bodies may be placed at first, 
they gradually approach one another at the apex of the 
nucleus and fuse together into the single large body already 
mentioned, which presents the same appearance and reaction 
towards stains as the two original bodies. It is at first in 
close contact with the nucleus, and the nucleus still lies about 
halfway down the basidium (Fig. 9). At a later stage the 
archoplasmic body makes its way to the top of the basidium 
and becomes removed, therefore, to some distance from the 
nucleus (Fig. 10). Soon afterwards, however, the nucleus 
itself makes its way to the apex of the basidium and is again 
placed in close contact with the archoplasmic body. It looks 
as if the archoplasmic body exerted an attractive force upon 
the nucleus (Fig. 11). The nucleus is now in position for 
division, which always, without exception, takes place at the 
upper end of the basidium. While these changes have been 
taking place the nucleolus takes up a position at the base of 
the nucleus, so that we have now the archoplasmic body at 
the apex and the nucleolus at the base (Fig. 12). The 
nucleolus gradually loses its capacity for deep staining, and 
at the same time the nuclear threads become more and more 
deeply stained and are gradually removed to the apex of the 
nucleus, as already described in my previous paper 1 (Fig. 13). 
The threads become gradually divided up into the chromatic 
elements, which stain a deep bright red, the nucleolus be- 
comes fainter and fainter in colour, the nuclear membrane 
gradually disappears and the remains of the nucleolus are 
extruded into the protoplasm, where they often divide up 
into two or more small spherical bodies (Fig. 16) and finally 
these completely disappear. 
While the chromatic elements are being thus developed, the 
centrosphere undergoes a change. At first it is seen in close 
contact with the nuclear threads, as they accumulate at the 
Loc. cit. 
