410 Cutting . — On the Sexuality and Development of 
in the end cells which grow out. The cells near the ascogonium get more 
and more vacuolated, and their nuclei seem to degenerate. Sometimes 
a solitary nucleus may be seen in a cell of an ascogenous hypha ; at other 
times as many as three or even five in one section. This latter case is 
somewhat against the view of a binucleate series of nuclei in the ascogenous 
hyphae. Four nuclei in one cell may be regarded as an example of a 
nuclear division not yet followed, by a cell-division but the presence of five 
nuclei is incapable of any such explanation. 
The ascogenous hyphae make their way between the cells of the fruit 
and amongst the bases of the paraphyses, branching much during the pro- 
cess, and also twisting in all directions. The portions embedded in the 
hypothecium are distinguished from the surrounding cells by paucity 
of content, and the parts in the region of the paraphyses by the density 
of the protoplasm. As the paraphyses themselves are much richer in 
protoplasmic contents than the hypothecial cells, it will be seen that 
the difference between these two portions of the ascogenous hyphae is very 
marked indeed. A similar state of affairs is reported by Harper for 
Ascobolus (20). As in this latter genus it seems very probable that the 
young ascogenous hypha obtains most of its nourishment from the sur- 
rounding tissue and not from the ascogonium, from which indeed it soon 
loses its connexion, the young ascus probably receives most of its food 
from the paraphyses. 
After the emptying of the ascogonium by the ascogenous hyphae, the 
remaining nuclei degenerate (Figs. 14, 21 a and b, 22), passing through 
stages very much like those described by Davis (12) for the degenerating 
nuclei in the oogonium of Saprolegnia , becoming more and more vacuolate, 
swelling up, and finally disappearing. The ascogonium-walls are forced 
inwards by the pressure of the surrounding cells, and soon the whole struc- 
ture is unrecognizable. In the case of ascogonia which are vertically placed 
in the fruit, the ascogonial cells are first drawn out (Fig. 21 a and b) before 
their total disorganization. 
The Ascus. 
The ascogenous hyphae bend over at the tips (Fig. 15 a) and form the 
characteristic bent end, from the penultimate cell of which the ascus 
is formed with the usual fusion of two nuclei (Figs. 1 $ a, b, c, d , 16). This 
latter process is sometimes somewhat delayed. 
As the ascus gets larger and larger a series of vacuoles make their 
appearance above and below the nucleus, and the protoplasm in these 
regions becomes more and more vacuolate until only the protoplasm 
immediately around the nucleus and at the extreme tip of the ascus is free 
from vacuoles (Fig. 19). At the tip the protoplasm is extremely dense, 
especially at that portion where the lid is formed, by which the ascus opens. 
