July, 1922] BONNS — A STUDY OF CLAVICEPS PURPUREA 
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progressed slowly until checked by the drying down of the media (PI. 
XVII, fig. 4). No conidia formation and no sterigmata were noted in the 
dishes. On the agar slants spores were very numerous. 
The cycle from germination to spore formation in the first stage of 
activity appears to be surprisingly short. Simple fission appears to be 
a not uncommon mode of multiplication, and spore formation by re- 
peated budding or by the development of a short tube, which then appears 
to be abscised as one or more spores, is common. Occasionally a spore 
develops into a promycelium of 150-250 /i with very short side branches 
of 4-10^1, or less, the latter developing terminal conidia. The spores, 
generally ellipsoidal in form, show great variations in size and outline 
(PI. XVII, fig. 3), ranging from 2.3 to 10.6 m in length and from 1.2 to 
4.2 ju in width. Such variations may perhaps be ascribed to different 
stages with respect to germination. Germination from the two poles is 
quite common (PL XVII, fig. i), a fact noted by Kuehn (11). Spores 
are frequently septate before germination, and sometimes the wall appears 
after the formation of a promycelium. The bipolar granular areas noted 
by Brown and Ranck in spores of C. Paspali, and which Meyer in his 
study regards as oil drops in C. purpurea, are conspicuous (PI. XVII, 
figs. 2,7,9). 
Following the mycelial development just noted, fresh inoculations 
from the same source were made on the same agar media in small 50-cc. 
Erlenmeyer flasks and on plugs of carrot, potato, and turnip. In addition, 
loo-cc. Erlenmeyer flasks containing mashes of white corn meal, ground 
rye seed, and ground rye screenings were used in this series. The inocula 
were taken from the area of vermicular growth. The new growths upon 
agar in the flasks repeated the vermicular character until they had attained 
an average size of 2 to 3 cm. in diameter (PI. XVI, figs. 1,2). Following 
this stage, the surfaces of the media were gradually covered by a very 
thin, silvery mycelium. No aerial mycelium developed in any agar cul- 
tures for several weeks following inoculation. As growth progressed, the 
central areas in some agar flasks formed a pellicle, becoming raised and 
slightly folded and convoluted but not in a manner to form the intricate 
vermicular type of growth (PI. XVI, fig. 3). The mat developed a thick- 
ness of somewhat less than a millimeter. Studies of the central and periph- 
eral portions showed a great predominance of spores in the former and 
a great mycelial development in the latter. 
No growth was obtained on turnip, and a very moderate vermicular 
growth developing sparse mycelium resulted on potato. On carrot plug 
growth was rapid and abundant. Within 24 hours following inocu- 
lation with a gelatinous portion of the inoculum, this had spread 
over three fourths of the carrot slant, and within a very few days 
this growth resulted in a very dense white mycelial cushion which rapidly 
penetrated the tissue of the plug. This mycelium conformed with descrip- 
