748 Wisconsin Academy of Sciences, Arts, and Letters. 
with the chromatin, locates a polar region where the chromatin 
must aggregate when contracted. 
Maire’s further attempt! to bring the divisions of the nuclei 
of the aseus into harmony with the latest views regarding re¬ 
duction division in the higher plants has led to his adoption 
not only of the fusion of two spirems, as described by Allen 
(1) for Lilium, but also the pairing of protochromosomes to 
form the real chromosomes, comparable to the formation of 
Strasburger’s zygosomes (23). 
It is also plain in Microsphaera that the delimitation of the 
spores is accomplished by the activity of the astral rays which 
persist from the third nuclear division. As described, the 
growth and increase in number of the astral rays is accompa¬ 
nied by the formation of a beak on the polar end of the nucleus 
(Fig. 12). At the same time, the nucleus and aster move 
away from the aseus wall toward the interior of the ascus. 
The fibers bend down around the nucleus and grow in a curved 
line toward a point directly below the nucleus, where they fi¬ 
nally meet. Lateral fusion of the rays begins at the polar re¬ 
gion and progresses outward toward the base of the spore, 
forming a complete membrane about the ovoid mass of proto¬ 
plasm, which, with the enclosed nucleus, forms the ascospore. 
The motion of the fibers through the cytoplasm cannot be due 
to crowding resulting from an outward movement of the nuclei 
toward the wall as Faull suggests, for at this time in Micro - 
sphaera the nucleus and the aster move in from the ascus wall. 
His other hypothesis that the “centrosome is a dynamic center 
and the rays an expression of cytoplasmic activity controlled 
by the nucleus,” causing the rays “to turn toward the bulk of 
cytoplasm which lies centrad of the centrosome,” is based 
on a confusion of two entirely separate views of the centro- 
some, first as a dynamic center, and second as a center of meta¬ 
bolic activity. It seems probable, however, that the rays 
are something more than cytoplasmic particles arranged along 
lines of force, since, as described above, after they have begun 
to fuse they can be separated from the cytoplasm by plasmoly¬ 
sis. Faullk further argument that the bending of the rays 
throws them further apart rather than brings them closer to- 
