July, 1922] BONNS — A STUDY OF CLAVICEPS PURPUREA 
345 
mycelia, have not, even when of considerable age, shown a marked vacuo- 
lation or massing of protoplasmic contents as a general characteristic. 
There appears to be a marked relation between the early gelatinous-ver- 
miculate stage of growth and a lack of normal mycelial development. In 
this stage, our studies show an extremely short cycle from one spore genera- 
tion to another, as previously noted. It is in this area of prolific spore 
production that the short, partially vacuolate hyphae have been most 
generally observed (PI. XVII, fig. i, A, C; fig. 6). The protoplasmic 
contents are generally segmented areas of the size and form of spores 
in early stages. In addition, mycelium in early stages of development has 
frequently been noted in which non-terminal cells were swelling and assum- 
ing the spore form (PI. XVII, figs. 7, 8, 9). We incline to the view that 
the phenomena above noted may be regarded as responses by the fungus 
to cultural conditions and that these growth abnormalities indicate the 
probability of chlamydospore formation. 
The final series of cultures in this preliminary study consisted of 500-cc. 
flasks containing mashes of white corn meal, yellow corn meal, white 
potato, sweet potato, carrot, rye seed, rye screenings, string bean, and 
rye heads after flowering (PI. XVIII). The latter medium consisted of 
entire rye heads collected shortly after the flowering period, dried, and 
finely ground. The weight of solid material used in each case varied from 
ICQ grams in the case of the corn meals to 300 grams for green string beans, 
with a corresponding variation in the amount of water added in each case, 
so that the respective substrates after autoclaving resulted in compact 
solid masses with a water content sufficiently great to overcome the des- 
iccation factor for an extended period of growth. The flasks were inocu- 
lated in mid-September, 1920, with inocula from the vermicular area of 
one of the preceding agar cultures in flasks. 
Response to different media was indicated by marked variation in 
both rate and character of growth. That on sweet potato was the most 
rapid in the initial stage, the entire surface of the medium being covered 
with very vigorous aerial mycelium in about one week. At the same 
time, growths were moderate on the two types of corn meal and on rye 
seed; string bean and white potato showed slight growth of the com- 
monly observed gelatinous character. Carrot, contrary to the results 
of our previous work, showed remarkably slow growth. The flask of rye 
heads showed only a trace. This latter material was not in a compact 
form, due to its agitation as the result of autoclaving, but we succeeded 
at this time in shaking the material up and spreading the inoculum, so 
that better growth resulted thenceforward. The rate of growth after the 
first week did not maintain the same relative pace, and three months 
after inoculation the most abundant growth was again to be seen on the 
two corn meals. In these media the marked purple color and heaping 
up of the mat in vermiculate form somewhat resembling sclerotia were 
