308 Wisconsin Academy of Sciences, Arts, and Letters. 
trichogyne from the oogonium. The opening in the basal cell wall 
of the trichogyne then closes. The male and female nuclei in the 
oogonium then fuse in pairs. As there are more egg nuclei than 
male nuclei many of the former fail to find mates and are later 
disorganized. The female nuclei aggregate in the center of the 
oogonium previous to fusion, but after fusion migrate to the 
ascogenous hyphae which are produced from bud-like outgrowths 
from the oogonium at the time of the formation of a pore in the 
basal wall of the trichogyne. The ascogenous hyphae grow and 
branch profusely, their ultimate branches giving rise to the asci. 
At first each branch contains two nuclei. These nuclei are not sis¬ 
ter nuclei but come from different nuclei in the ascogenous hyphae, 
each nuclei having descended from one of the original pair in the 
ascogenous hyphae. Possibly each one is a direct descendant of 
one of the daughter nuclei of the fusion nucleus and the two nuclei 
in the ascus therefore represent two distinct lines of descent. 
The two nuclei in the branch, which is curved, forming a shep¬ 
herd’s crook, divide simultaneously and form four nuclei. The 
spindles are so placed that a pair of nuclei are left in the crook, 
one from each spindle, so they are not sister nuclei. The other two 
nuclei, each the daughter of a different mother nucleus, migrate 
from the spindles, one going to the apical region of the branch, 
the other to the basal region. Two partition walls are then laid 
down making three cells out of the branch, the apical cell contain¬ 
ing the single apical nucleus, the middle cell containing two nuclei, 
and the basal cell containing the nucleus that migrated to the basal 
region. The middle cell lies in the crook of the branch and is some¬ 
what dome-shaped. It now forms the ascus, the two nuclei in it 
fuse to form the primary ascus nucleus. The nuclear fusion is 
followed by three successive divisions that are similar to those al¬ 
ready described by Harper for other Ascomycetes. 
The results of Harper’s (1905) study of Phyllactinia corylea 
substantiated his earlier work. The sexual apparatus is formed 
where two hyphae cross or lie close to each other. The oogonium 
and antheridium become applied and spirally twist about each 
other. A portion of the walls between them is dissolved and the 
single nucleus of the antheridium migrates through the pore into 
the oogonium. It fuses with the somewhat larger nucleus of the 
oogonium and the pore through which it entered closes. After 
nuclear fusion, or just previous to the migration of the male 
nucleus, the stalk cell of the oogonium produces paraphyses to form 
