177 
produce setm, seems to favor the notion that they may serve as peculiar 
resting bodies produced more abundantly in unfavorable conditions, 
and later capable of producing mycelia again. 
I have observed these same peculiar cells preceding the formation of 
sclerotia, and intermingled with them in the case of Vermicularia cir- 
cinans on the onion. This is additional testimony regarding the close 
relationship existing between some of the species of Colletotrichum and 
Vermicularia. 
Parallel with the artificial cultures, inoculations were made of seed¬ 
lings grown in a frame. A portion of a boll containing a profuse devel¬ 
opment of spores was immersed in distilled water which was then shaken 
thoroughly. The cotyledons of the plautlets were well wetted with 
this. A bell jar was then placed over them for twenty-four hours. An 
attempt was then made to imitate as nearly as possible the natural con¬ 
ditions of temperature and humidity, which seem to favor the early 
development for a few days. By artificial heat temperatures ranging 
from night to midday, 20° to 35° 0. were produced. The humidity of 
the air in the frame was also kept above that of the open air by keep¬ 
ing the frame closed, having but little ventilation and wetting the soil 
daily. After the fourth day the humidity was reduced while the tem¬ 
perature was maintained. It was not found necessary to inoculate at 
incisions in parts of the plant. 
A week later an examination was made of a cotyledon which was 
dying, the distal end being half dead and shriveled while the base was 
still green. It was well infected, and there were numerous clusters of 
setm at the edge, also clusters of spores, and in the interior of the 
cotyledon spores borne on scattered basidia. Ten days from the time 
of inoculation another plantlet was diseased, both cotyledons being 
affected. When the distal half was pretty well dead and shriveled the 
examination was made. Very few external signs of the fungus were 
present, but in a few places at the edge the setm were just piercing 
through, and sections showed numerous spores and clusters of the 
special bodies which bear the setae. The base of each cotyledon was 
apparently healthy and each was still firmly attached to the stem. 
I have not yet attempted to inoculate the plants in any other way 
than through the cotyledons, but the success attained has suggested 
that perhaps the plants when not injured in any way are only liable to 
infection through the cotyledons as in the well-known cases of Cys- 
topus candidus in different species of Cruciferce. How far this is true 
must be determined by future experiments. 
The Colletotrichum on cotton seems to have been hitherto an unde¬ 
scribed species. Since completing this work thus far I found that Miss 
E. A. Southworth had been giving the fungus some study, having had 
specimens of it on cotton bolls. She has proposed the name Colleto - 
trichum gossypii , n. sp., which is eminently appropriate. 
