180 Barker .— The Morphology and Development of 
They are thus clearly defined. In certain parts, particularly 
in the antheridial branches after fusion with the ascogonia, 
an intermediate method of staining is found. The bodies of 
the nuclei stain uniformly but not deeply, while a distinct 
network of more deeply stained material is visible and an 
inconspicuous nucleolus is usually seen. 
In both the antheridial branch and the young ascogonium 
there are numerous nuclei. At the time of fusion several may 
be found in both organs close to the place where fusion occurs, 
especially in the antheridial branch (Fig. 15 a). After fusion 
no doubt a migration of nuclei occurs from the latter into the 
ascogonium. At this time the canal between the two organs 
is practically indistinguishable, and it is impossible to deter- 
mine clearly if nuclei are situated in it. 
The occurrence of several nuclei in its neighbourhood is, 
however, significant ; and in many cases nuclei appear to 
occupy the passage (Fig. 15, a). At a slightly later stage, 
when the canal is more easily seen and the central cell has 
been cut off by the formation of a wall, a nucleus can occa- 
sionally be found in the passage (see Fig. 15, b). 
The ascogonium, after fusion with the antheridial branch, 
contains a large number of nuclei ; and the central cell, when it 
is first cut off, seems to be almost entirely filled with them. 
They are not clearly defined on account of the affinity of the 
protoplasm for the stain and the slight staining capacity of 
their bodies. Their nucleoli alone are conspicuous (Fig. 15, b). 
Later, as the central cell grows larger, they are found grouped 
together at its centre in a dense mass (see Fig. 1 5, c ). 
The surrounding protoplasm is almost unstained, the 
nuclear bodies are now more darkly stained, and the nucleoli 
are not quite so conspicuous. Finally, when the central cell 
has attained a considerable size and is completely invested, the 
nuclei are scattered irregularly in it and are stained rather 
deeply and more uniformly. In the ascogenous hyphae the 
nuclei are not clearly defined, the staining of the younger 
branches being in particular very diffuse. Occasionally a few 
are found which show a structure similar to those of the 
