508 Wager. — On Nuclear Division 
up a position on that side of the nucleus nearest to the wall of 
the basidium and for a short time after their appearance here, 
a few delicate faintly stained blue threads can be seen traver- 
sing the cavity of the nucleus (Fig. 45). These soon disappear 
however, as well as the nuclear membranes, so that the nuclear 
elements come to lie, at an early stage, quite freely in the 
cytoplasm (Fig. 46). The nucleolus, meanwhile becomes much 
smaller in size and loses its capacity for taking up the red stain. 
The chromatin-granules forming the equatorial plate in each 
nucleus are arranged more or less regularly in a ring, which 
appears perfectly homogeneous under a low power of the 
microscope. The arrangement recalls that seen in the equa- 
torial plate of the higher plants. The formation of the spindle 
and the separation of the chromatic elements takes place as in 
A. stercorarius. 
The chromatic elements, in both species, as soon as they 
reach the poles of the spindle, fuse together and present 
a more or less homogeneous appearance. Then the old 
nucleoli disappear and soon afterwards a nuclear membrane 
is formed around each daughter-nucleus. Out of this fused 
mass of chromatic elements, a nuclear-network becomes 
gradually differentiated which stains blue like that in the 
parent nucleus, and the remainder of the chromatic substance 
appears to become transformed into the nucleolus (Figs. 24 
and 47). 
The four daughter-nuclei increase in size until they take up 
nearly the whole of the diameter of the basidium. They 
arrange themselves in a transverse plane near its apex, and 
transverse sections through this region of the basidium, at this 
stage, show the four nuclei very clearly. 
The four nuclei now begin to move towards the base of the 
basidium, and at the same time the sterigmata begin to form 
as four small projections near the apex (Figs. 25-27). At the 
base of the basidium the nuclei, which have hitherto been 
spherical in outline, become more irregular and come into 
such close contact with one another that it becomes difficult 
to observe their outlines at all (Figs. 27 and 28). Finally they 
