334 Wisconsin Academy of Sciences, Arts, and Letters, 
The ostiole is formed at the apex of the perithecium. The outer 
zone of cells becomes disorganized, and some of the cells appear 
plasmolyzed or devoid of staining material. Pressure due to 
swelling of the gelatinous material within the perithecium may 
rupture the upper portion and form the small opening known as 
the ostiole. If enzyme activity is necessary to dissolve some of 
the tissue, the inability to discharge spores before a certain ma¬ 
turity is reached might be explained. The gelatinous material 
within may require certain chemical changes to increase its swell¬ 
ing capacity, thereby limiting the period when spores may be dis¬ 
charged. If this material would simply by swelling cause the 
rupture of the perithecium, the discharge would be entirely a 
mechanical process. In the ostiole filaments appear as if the dis¬ 
solution and pulling apart had left some of the fibres intact. The 
perithecia at this time are greatly elongated and have the appear¬ 
ance of forming a bottle neck at the upper end. There is very 
little staining capacity left in the tissue comprising the wall; 
evidently the cell contents have disappeared. 
The nuclear behavior was not followed clearly owing to the 
difficulty of staining the chromatin. As previously stated, no nu¬ 
clear fusion was observed in the ascogonium, although many prep¬ 
arations of the stages when fertilization occurred and those im¬ 
mediately following it were made. The nuclei in the ascogonium 
after fertilization increase tremendously in size and are paired. 
Two and four nuclei are found in a cell. The contents of the nu¬ 
cleus may stain densely or scarcely at all. No attempt was made 
to follow the behavior of the nuclear contents during growth and 
division. Some sections prepared at the time the spores are de¬ 
limited in the ascus indicate that a central body exists whose 
fibres function in cutting out the spore, in a manner similar to 
that described by Harper (1897) (1905). 
The work of Killian (1915) indicates that he found sections 
showing the large trichogyne and the coiled ascogonium. My 
preparations failed to show the antheridium branched as he figures 
it, but some of my sections show lobes of the tip or apical cell of 
the antheridium closely applied and partly surrounding the tri¬ 
chogyne. The nuclei aggregate near the pore and pass into the 
trichogyne sometimes in bead-like rows. Most of my sections in¬ 
dicate that the ascogonium is composed of five to eight cells and 
that these cells are formed after fusion with the antheridium. 
Killian’s figures do not indicate that the ascogonium is divided 
