SPORE FORMATION IN PHILOCOPRA COERULEOTECTA 63 
The asci were of fairly good size and appeared favorable for the 
study of their development and the formation of the ascospores in a 
many-spored form. The many-spored forms are looked to for evi- 
dence on the question whether the ascus is in any way related to the 
sporangium found in the Phycomycetes. The process of delimitation 
in a many-spored ascus; the stage when delimitation occurs; the 
presence of a central body; and the relation of the epiplasm and 
spore-plasm are subjects of considerable interest in the study of the 
relationships of the Ascomycetes. 
The material for this study was fixed in Flemming's weaker solu- 
tion and Strasburger's modification of Flemming's medium. Both 
afforded excellent fixation. The sections were stained with modi- 
fications of Flemming's triple stain and Heidenhain's iron-haematoxy- 
lin. 
There was no trouble in getting an abundance of the material in 
all stages of development. The fruiting bodies, together with the 
adjacent mycelium, were fixed in large quantities. The substratum 
was included in many cases in order to get all stages. It proved to 
be very easily sectioned. There was considerable variation in the 
stages of development among the different asci in a pyrenocarp. 
Sometimes mature spores and very young asci were found in the 
same fruiting body. There were always at least several stages to be 
found until the pyrenocarp reached its full size. 
The pyrenocarp is flask-shaped. The wall is composed of several 
layers of closely packed hyphae, the walls of which stain darkly. 
From its base arise a number of asci among which are seen numerous 
paraphyses. Often the asci in a single pyrenocarp are in various 
stages of development. There is considerable variation in the number 
of asci to be seen in a pyrenocarp, depending somewhat on its stage of 
development. Figure i represents a longitudinal section through a 
pyrenocarp. It shows the typical flask shape with the opening in 
the neck at the apex. This section shows three immature asci with 
numerous ascospores. Often as many as eight or ten asci may be 
seen in a single pyrenocarp with the spores at different stages, afford- 
ing a good opportunity to trace the progressive steps in their develop- 
ment. Younger ascocarps are, however, more favorable for the study 
of the young stages before spore formation begins. 
In figure 2 is shown a very young ascus. It was located very 
near the base of the pyrenocarp. The rounded upper portion contains 
