Martin—Taphrina Coryli Nishida on Corylus, 
349 
other times to be in late metaphases and anaphases. The nueleole 
disappears at the time of the spindle formation, but no indications 
of the division of a central body to form two daughter centers, as 
described by Harper (1899, 1905), are seen. The reorganized 
nuclei are typical resting nuclei, each containing one nueleole 
(fig. 25). 
The Formation of the Basal Cell 
Each mature ascus of Taphrina coryli Nishida has a basal cell, 
but the time of the formation of the septum varies. Often before 
the division of the fusion nucleus is complete, the plasma mem¬ 
brane in the lower part of the ascogenous cell begins to constrict 
(fig. 23). Again, the plasma membrane may not begin to constrict 
until after the daughter nuclei are fully formed. It may be that 
vacuolar membranes also play a small part in the formation of the 
cell plate, for vacuoles are frequently in such a position that vacu¬ 
olar membranes meet the constricting plasma membrane (fig. 25). 
Many cases were observed, however, which suggest that the con¬ 
stricting portions of the plasma membrane have stretched out to 
meet each other, forming a cleavage furrow in which will be laid 
down the cell wall (figs. 26, 27). From a study of a number of 
such cells, it seems safe to conclude that the process of separation 
of the ascus cell proper from the basal cell is initiated either before 
or just after the first nuclear division is complete. One of the 
nuclei formed by the division of the fusion nucleus passes to the 
upper part of the ascus where it later undergoes division, the re¬ 
peated divisions of its daughter nuclei forming the nuclei for the 
eight primary spores. The other nucleus formed from the fusion 
nucleus remains in the lower part of the ascus, w^hich becomes the 
basal cell. The nucleus of this cell persists for a while and then 
disintegrates; the only remains of it being in the form of chromatin 
granules which are left in the cytoplasm for a time (fig. 28). As 
the ascus grows older, even the chromatin granules disappear, and 
the cytoplasm, which has been quite dense, now becomes more and 
more vacuolate (fig. 29), until it, too, completely disappears in the 
basal cells of the older asci (figs. 31, 33). These would conform 
to the empty basal cells figured by Atkinson (1894) for Exoasctis 
deformans, Exoascus cerasi, and Exoascus decipiens. Sadebeck 
(1893) in Taphrina Sadeheckii Johns, and Miss Bitner (1915) 
in Taphrina coryli also found empty basal cells with the older asci. 
