512 Harper. — Cell- Division in Sporangia and Asci . 
chromatin lies for the most part on the nuclear membrane and 
is still in lumps and masses rather than threads or granules. 
A beak-like prolongation of the nuclear membrane beneath 
the central body and aster has appeared, and the nucleus has 
come to lie a little further from the plasma-membrane of the 
ascus and may be inclined at almost any angle to it. It will 
be readily seen that the nuclei being distributed on the inner 
walls of the cylindrical ascus, with the axis of the nuclear 
figure placed in general radially to the plasma-membrane, the 
beaks and asters will appear in polar view, in the case of such 
nuclei as have the beak-like prolongation extending vertically 
upward or downward from the plane of the section. Of the 
six nuclei appearing in this figure this was the case with 
the second and third nuclei from below, which extended 
almost vertically downward from the upper surface of the 
ascus, and their centres and asters do not appear in the figure. 
In this section some irregular openings appear in the spore- 
plasma and frequently red-staining granules are associated 
with them, lying on their borders but never free in their 
interior. In such cases the appearance suggests that the 
openings are due to breakage of the protoplasmic framework, 
whose elements have then shrunken together in the form of 
dense granules on the margins of the rents. This suggests 
that these red-staining extranuclear nucleoli may be formed 
artificially by partial breaking down of the protoplasmic 
structure in fixation. Whether this is a general explanation 
of this very common appearance in the cells of higher plants, 
I have not been able to satisfy myself. The process of meta- 
morphosis of the aster in cutting out the spore is essentially 
the same as in Erysiphe. The rays revolve on the central 
body, and the cone-shaped opening, triangular in optical 
section, which indicates the first motions of the aster-rays is 
well shown in the case of the lower nucleus in Fig. 43, and in 
the upper nucleus in Fig. 44. The asters being in contact 
with the plasma-membrane, the latter seems to be pulled in as 
the fibres fold over, and thus a depression is produced in the 
surface of the protoplasm of the ascus. At first the central 
