398 
Freda M. Bachmann 
with a tiny globular nucleus at eac-h end (Fig. 61). The aseogenous liyphae, 
to some extent interlaced with vegetative hyphae, come to form quite 
a dense tissue below the hymenium (Fig. 64, PI. XXXV). In many cells 
there are two nuclei but many other cells contain each a single nucleus. 
The nuclei of the aseogenous hyphae are eonsiderably larger than those 
of the vegetative hyphae in tliis region (Fig. 64). 
Bv the time tliis tissue of aseogenous cells has been formed below 
the paraphyses, the fruit body has enlarged and is no longer spherical. 
The algal cells which are crowded above the hymenium near the surface 
of the tliallus are seen to be disintegrating, and onlv a gelatinous layer 
forms a covering through which the developing apothecium bursts. The 
first asci are formed shoitly before the hymenium becomes exposed. 
Because of the very dense structure of the hypotheeium I have not sue- 
ceeded in determining without doubt just how the asci are formed from 
the aseogenous hyphae. In a few cases the end of the hook described 
for many other ascomycetes, from whicli the ascus arises, was rather 
doubtfully to be seen. 
It is not difficult to find young two-nucleate asci. The two nuclei 
do not fuse until the ascus has elongated eonsiderably. In Figure 67, 
the two nuclei lie elosely side by side. There is a eonspieuous red-staining 
granule at the lower end of each nucleus which may be a centrosome. 
The chromatin is usually distributed on the nuclear membrane, and 
not infrequently granules in the cytoplasm are also in direct contact 
with the nuclear membrane. In another young ascus (not figured) whose 
nuclei have just fused, there are two granules outside on the nuclear 
membrane and very dose together. These again suggest that the two 
masses in Figure 67 are probably centrosomes. If these are centrosomes, 
there is no visible connection between them and the chromatin. In the 
primary ascus nucleus the chromatin is aggregated into a very irregulär 
spirem which is at first thin and smooth tliroughout, but is later made up 
of more or less rounded masses of chromatin. The nucleus enlarges with 
the growth of the ascus and does not divide until the ascus has grown 
to its full length. The nucleole is usually excentric, quite large and ap- 
parently liomogeneous. It has enlarged with the growth of the nucleus, 
and since the chromatin has also increased in bulk it cannot be that the 
chromatin comes from the nucleole. The number of chromatin masses 
in the spirem appears not to vary greatly in number. In synapsis, the 
spirem is drawn into a quite compact mass in which some of the chromatin 
masses may still be seen. The position of the synaptic knot has no re- 
lation to that of the nucleole. After synapsis the chromatin is again in 
