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AMERICAN JOURNAL OF BOTANY 
[Vol. 9, 
tions of Brefeld and of Meyer, showing typical hyphae and spore formation 
with great numbers of abscised spores arranged in parallel fashion along 
the threads. A similar grouping was commonly noted in growths on 
agar (PI. XVII, figs. 5, 7). 
Of the three growths on the mashes, that obtained on the rye screenings 
was an extremely sparse aerial mycelium. On the rye-seed mash a growth 
of the usual gelatinous- vermiculate type started, which covered the surface 
of the media in about a week or ten days. From this stage resulted a 
very dense mat of aerial mycelium, which in the course of several weeks 
showed a slight tendency to assume a pinkish or purplish hue. The growth 
upon white corn meal was so rapid and so similar in character to the surface 
of the corn meal after sterilization that it was difficult to note its progress 
until it had reached the side of the flask the second or third day after 
inoculation. Three weeks from the time of inoculation the entire surface 
and a very large portion of the medium bounded by the sides of the flask 
were covered with a dense mycelial growth which became strongly con- 
voluted and took on a deep purple-black color similar to that of the scle- 
rotia of Claviceps. As time progressed, the invasion of the fungus con- 
tinued, although somewhat checked by the gradual drying of the medium. 
The aerial mycelium in the agar flasks, on the other hand, did not develop 
uniformly on all three kinds of media, or over the entire surface in any 
one, but appeared as isolated areas or as a ring. 
On agar in Petri dishes, where the growth was confined to the surface 
and no pellicle of any thickness developed, there was observed the parallel 
massing of hyphae in strands of from two to five or six threads, which 
Meyer describes as a morphological variation of the organism on solid 
media. 
We have been unable to confirm this view. No morphological relation 
of the fungus to solid media of any kind has been observed. On the several 
kinds of agar other than that in the Petri dishes, and on the other organic 
solid media with abundant water content, the mycelium developed the 
usual branching form regarded by previous workers as normal. We incline 
to the view that the growth variations noted may possibly be a reaction 
to a surface-tension factor associated with low water content of the medium. 
Strands of parallel hyphae were occasionally observed in the same field 
with branching mycelium. There also appeared to be two types of hyphal 
development, the threads of one type being two to three times broader 
than the smaller, predominating kind. The broader filaments were in 
some instances split at the tips to form long sterigmata, but no spores 
were observed in such cases. 
Our observations also conflict with Meyer's views regarding the greater 
age of the vacuolated mycelium. In our cultures the latter was most 
frequently found in the areas of earliest growth, namely in the vicinity 
of the inoculum. The hyphae of later development, especially the aerial 
