264 
Journal of Agricultural Research 
Vol. I. No. 3 
Corn Meal (1061 1 ) 
2 days.—No visible growth. 
4 days.—Yellowish white growth about 1 cm. in diameter. Hyphae growing close to 
the medium. 
7 days.—Hyphal growth about 4 cm. in diameter, slightly yellowish. Numerous 
minute black pycnidia covering an area of about 2 cm. in diameter in the 
center of the growth. 
9 days.—Hyphal growth covering most of the surface of the medium and pycnidia 
formed over about two-thirds. Spores just beginning to exude from pycnidia. 
11 days.—Pycnidia covering most of surface of medium; exudate of spores forming 
small viscid droplets. 
14 to 17 days.—Abundant discharge of spores from the pycnidia. 
21 days.—Spore discharge collecting in large globules, forming an almost continuous 
covering over the surface of the medium. 
25 days.—No change. 
40 days.—Surface of medium completely covered with a slimy liquid containing 
pycnospores. 
67 days.—Hyphae hyaline. Numerous intercellular and terminal chlamydosporelike 
bodies. 
Com meal is the best of the media used for the development of pycnidia. The 
pycnospores are first expelled in about one week, the process continuing for 30 or 
40 days thereafter. At the end of that time the medium is covered with a slimy 
liquid in which the spores are suspended. This liquid, often amounting to 5 c, c., 
is characteristic of growth on this medium and is apparently not due to the water 
added, since that is taken up by the corn meal. 
String-Bean Agar (1037) 
4 days.—Sparse white growth. 
7 days.—Heavy, white flaky growth of erect hyphae covering one-fourth of slant. 
9 days.—Light-colored pycnidia collected in spots on surface of medium. 
11 days.—No increase in mycelial growth; pycnidia dark; pycnospores exuding from 
r**. pycnidia. 
14 to 17 days.—Perceptible increase in the exudation of pycnospores. 
21 days.—Exudate colorless, forming large droplets and uniting. 
25 days.—No apparent change. 
40 days.—Hyphal growth covering most of slant. Spores normal. 
67 days.—Hyphae hyaline. A few chlamydosporelike bodies. 
String-bean agar is only a fair medium for the growth of this fungus. The pycnidia 
were sparingly formed as compared with the growth on com meal. 
String Beans (1063) 
4 days.—White, loose, flaky growth covering one-third of medium. 
7 days.—White, loose, flaky growth covering three-fourths of medium. 
9 days.—Felty grayish white growth of somewhat erect hyphae. Pycnidia collected 
in spots. Pycnospores present. 
11 days.—Pycnidia black. 
14 days.—Slight exudate of spores from pycnidia. 
17 days.—Slight increase in the discharge of spores. 
21 to 25 days.—Exudates uniting, colorless. 
1 A number is given to and a description made of each medium when it is prepared in the laboratory so 
that it can be readily duplicated when desired. Unless otherwise stated, all media were prepared in the 
laboratory of the Office of Cotton and Truck Disease and Sugar-Plant Investigations. 
