592 Brooks .— The Development of 
swollen and apparently mucilaginous, as do also the lower lateral walls 
to a lesser extent. 
The tufts of trichogynes are generally placed laterally in relation to the 
‘ coils Thus it is rare to see a group of trichogynes over the middle 
of a ‘ coil \ It is often evident that at least two series of trichogynes are 
associated with a single ‘coil’, but only very rarely are two such groups seen 
in a single section. In all cases examined it was only possible to trace 
a connexion between the trichogynes and the outermost cells of the ‘ coil ’. 
The trichogynes could never be traced to any structures resembling ascogonia, 
so must therefore be looked upon as mere continuations of ordinary vegeta¬ 
tive hyphae belonging to the ‘coil’. Fisch ( 15 ) and Frank ( 16 ) state that 
in Polystigma rubrum the trichogyne is the termination of a clearly differen¬ 
tiated archicarp. In this respect, therefore, Gnomonia differs considerably 
from Polystigma. 
The apical cell of each trichogyne is long and narrow, and generally 
contains a single nucleus (Fig. ii) ; occasionally a second nucleus is present. 
The first septum below the extremity of the trichogyne is approximately at 
the level of the inner wall of the epidermal cells, and below this region the 
identity of the trichogyne is lost, so that as a well-marked structure it is only 
one cell in length. It may be pointed out that the uninucleate condition of 
the apical cell of the trichogyne is the same as that found by Baur (a) in the 
corresponding structure of Collema , and by Darbishire ( 12 ) in Physcia. On 
the other hand, all the cells of the hyphae beneath the terminal cells of the 
trichogyne are multinucleate and, as has already been said, are scarcely dis¬ 
tinguishable at the time of their formation from cells of the general mycelium. 
At a later stage a few cells in the midst of the ‘ coil ’ become differen¬ 
tiated from those around by their larger size, their denser protoplasm, and 
by their larger and less numerous nuclei (Figs. 9, 10,11, 14). Though these 
cells often appear to be isolated from each other in a single section they 
really belong to one or more twisted filaments, as is ascertained by examin¬ 
ing successive sections. No pores such as occur in the archicarps of Asco- 
bolus ( 32 ) and Ascophanns ( 7 ) have been observed between the contiguous 
cells of these filaments. 
The nuclei of these special cells usually possess a distinct nucleolus, but 
no reticulum is visible, while the nuclei of the cells around contain several 
small chromatin granules and the nucleolus when present is very small. 
Furthermore, they are about twice the size of the vegetative nuclei. Nuclei 
of an intermediate character are sometimes visible in the larger cells in the 
centre of the ‘ coil \ Occasionally one or two exceptionally large nuclei are 
found in these differentiated cells. Such nuclei contain several deeply 
staining chromatin granules, but no well-marked nucleolus (cf. Fig. 11). It 
may be that these nuclei have grown immensely in size prior to division, 
but on the other hand they may be hypertrophied. 
