74 
HALLY JOLIVETTE SAX 
delimitation takes place in the same manner in all of the Ascomycetes. 
In some cases division may increase the number of spores. In other 
instances the nuclei may divide many times before delimitation takes 
place. 
The ascus can in no way be compared with the sporangium in 
the Phycomycetes. It is probable that further work would reveal 
still greater uniformity in the process of spore formation in the Asco- 
mycetes. Faull's assumption that the spores are delimited by the 
method found in the sporangia of the Phycomycetes finds no support 
in the many-spored Philocopra, where the process has been followed 
in detail. 
There is apparently a direct relation between the nuclear divisions 
in the ascus and the position of the spores. The first division is either 
crosswise of the ascus or obliquely so, thus bringing the two resulting 
daughter nuclei nearer the ascus membrane. The succeeding divi- 
sions take place near the periphery of the ascus. The later divisions 
are nearer the membrane. At the close of the division period the 
beaked nuclei with the central bodies come in contact with the ascus 
membrane and the spores are delimited. 
The important role played by the center and the nucleus in spore 
formation is apparent from their location near the region of greater 
activity. At the time of delimitation the nucleus and center are in 
contact with the ascus membrane. They are in contact with the spore 
membrane while the spore turns so that they point downward and 
outward. As the spore elongates they move back from the membrane 
to the opposite end, which increases in size and becomes the main 
body of the spore. The constant presence of the nucleus, with the 
central body, at the point where the main changes occur, suggests 
that they play more than a passive role in spore formation. 
Summary 
1. The study of a many-spored Ascomycete is important for the 
determination of the true nature of the ascus. Philocopra coeruleotecta 
Rehm, a new species, is well suited for the study because the spores 
are comparatively large and the asci are found at various stages in 
the same pyrenocarp. 
2. The cytoplasm in the ascus increases to a considerable extent 
before nuclear division begins. 
3. The first division spindle lies crosswise of the ascus. This 
