SPORE FORMATION IN PHILOCOPRA COERULEOTECTA 75 
brings the daughter nuclei nearer the ascus membrane. The nuclei 
in the following stages are near the periphery of the ascus. 
4. Successive nuclear divisions follow one another rapidly until 
one hundred and twenty-eight nuclei are formed. The increase in 
number of nuclei is accompanied by a decrease in size. 
5. At the close of the last division the nuclei are beaked. They 
are peripherally arranged in the central part of the ascus. The 
interior of the central part, the proximal portion, and the distal portion 
of the ascus contain cytoplasm devoid of nuclei. 
6. The beaked nuclei, with the central bodies, come in contact 
w^ith the plasma membrane. 
7. So far as observable spore delimitation occurs by the bending 
back of the astral rays and their subsequent fusion to form the spore 
membrane. 
8. The central body is present at all stages from the young ascus 
to the mature spore. 
9. The delimitation of the spores separates the cytoplasm into 
the spore-plasm, which is the dense part immediately surrounding 
the nuclei, and the epiplasm, which fills the remaining part of the 
ascus. 
10. At the time of delimitation the spores are ovoid in shape. 
The beaked nucleus and central body point toward the ascus mem- 
brane. Soon they turn around so that the central body and beaked 
nucleus point downward and outward. The spores elongate and grow 
obliquely upward toward the center of the ascus. 
11. The central body and the nucleus are always in close relation 
to the region of greatest activity. After delimitation when the spores 
elongate, they leave the spore membrane and move toward the oppo- 
site end of the spore. The latter grows and becomes the main part 
of the spore. It is spherical in shape. The lower part remains long 
and slender and forms the tail of the spore. 
12. A thick wall is laid down around the outside of the spherical 
portion of the spore. This is laid down by the spore-plasm. The 
epiplasm could not have played any role in the process since the wall 
between the tail portion and the main body is at least as thick as that 
of the rest of the spore wall. Yet the epiplasm was not in contact 
with the spore at this point. 
13. There is no indication of any phylogenetic relationship between 
the ascus and the sporangium of the Phycomycetes. The many- 
