539 
of the cuticle usually takes place in the middle, and the borders of the old cuticle 
are then later found surrounding the base of the young nemathecium (fig. 523 D). 
In other cases the bursting seems to take place at the periphery, and the nema- 
thecium is then covered by a calotte of cuticle originating probably from the sur- 
face of the stipe (fig. 523 E). 
In the young stages the ar- 
rangement of the cells may 
be rather irregular; some- 
times a single cell is seen 
to be more active and rich in 
cell-contents than the others, 
and producing a great part 
of the cells of the excrescence 
(fig. 523 A). The diameter of 
the quite young nemathecia 
is small, corresponding only 
to the diameter of a very 
small number of cortical 
cell-rows, but the diameter 
early begins to increase, 
the marginal growth taking 
place by vertical division 
of the marginal cells. The 
insertion of the nemathe- 
cium is, however, not en- 
larged by this process, the 
growing borders of the nema- 
thecium not being connected 
with the surface of the frond 
but separated from it by a 
slit (fig. 523 E, F) or in 
contact with it. The nema- 
thecium at the same time 
increases in height and is Fig. 523. 
then composed of parallel Phyllophora epiphylla. Young stages of nemathecia in September. 625 :1. 
or radiating filaments which 
later, in winter, produce tetrasporangia. As mentioned above, I have never seen a 
fusing process like that described by Scumirz; at all events it did not take place in 
the younger stages such as those represented in fig. 523. From the above it must be 
concluded that the nemathecia are the true organs of Phyllophora epiphylla and do 
not belong to a parasite. The name of Colacolepis incrustans must therefore be 
abandoned. 
69* 
