226 
Journal of Agricultural Research 
Vol. VIII, No. 6 
On cooked white com meal in flasks the mycelial growth is feltlike with somewhat 
cottony, pale purplish vinaceous to light pinkish cinnamon aerial mycelium at the 
surface of the medium. The sporulating parts are a Dresden brown to mummy-brown, 
while the sclerotial masses in old cultures approach a deep neutral-gray. Conidia 
are produced rather sparingly, but rounded to irregular black carbonaceous scierotia 
are produced abundantly after two to three weeks' growth. 
In lavender-blue litmus milk in test tubes a surface felt is formed with no growth 
in the lower part of the tube. Around the edge of the tubes the felt is slightly paler 
than pale purplish vinaceous with cinnamon to orange-cinnamon rings; while over 
the upper surface it approaches Dresden brown to mummy-brown. The casein is 
gradually precipitated, leaving a dark purplish supernatant fluid. The part above 
this shows no change in color when compared with check tubes, but bluish rings 
finally develop around the margin of the surface growth. 
On oxalic-acid-agar slants the surface mycelium at first approaches light purplish 
vinaceous, later becoming fawn color. The sporulating surface is nearly avellaneous. 
Conidia are sparingly developed, but are not as uniform in size or shape as on corn- 
meal agar. The red color of the medium (due to addition of neutral-red) becomes 
gradually bleached out, until in three to four weeks it assumes the color of plain beef 
agar. 
On potato-agar slants a Tilleul-buff cottony mycelium develops within a few days 
over the surface of the agar. A moderate number of typical conidia are borne on the 
finally somewhat feltlike mycelium. Even after two or three weeks there is no 
further increase in the number of spores borne. No scierotia have been noted. 
On cooked potato cylinders the appearance is somewhat similar to that on potato 
agar. The loose feltlike growth is Tilleul buff to vinaceous-buff in color. No conidia 
or scierotia have been observed even after three to four weeks. 
On cooked rice in test tubes a feltlike growth of shell-pink to buff-pink mycelium 
is formed. In four to seven days spores begin to develop, giving the surface a shade 
closely approaching Saccardo's umber. Conidia and scierotia are fairly abundant, 
but the latter are not so regular in shape as on cooked string beans. 
On cooked string beans the cottony mycelium covering the surface at first is a 
Tilleul buff varying slightly in shade on both sides of this color. The sporulating 
surface developed after four to ten days approximates a dark mouse-gray. Typical 
conidia are abundantly developed, and after one to three weeks there appear con¬ 
siderable numbers of roundish scierotia. These have all the external appearances of 
pycnidia or perithecia, but on breaking upon a slide, or sectioning, these were in¬ 
variably found to consist of a solid mass of fungous cells, and no spores of any kind 
were to be found. 
On synthetic agar 1 slants a thin feltlike mycelial weft covers the surface in a few 
days. This weft corresponds almost exactly to the shell pink of Ridgway’s chart . 2 
After about three weeks' growth the agar, which is a very dark brown at first, becomes 
bleached to about the color of plain beef agar. No spores, scierotia, or swollen cells 
are developed on this medium; but numerous round, highly refractive bodies occur 
in the hyphse. 
1 (i) i.soo c.c. of distilled water and 36 gm. of agar. Cook in double boiler for one hour at 15 pounds’ 
pressure. 
(2) 500 c. c. of distilled water, 200 gm. of dextrose. 40 gm. of peptone, 20 gm. of ammonium nitrate, 5 gm. 
of magnesium sulphate (crystals), ro gm. of potassium nitrate, 5 gm. of potassium acid phosphate (K2HPO4) 
and 0.2 gm. of sodium chlorid. 
Boil in double boiler for 30 minutes, add agar, and cook for five minutes. Restore to volume, titrate, 
cool to 6o° C., and add whites of two eggs. Cook to coagulate eggs; filter, tube, and sterilize. 
This formula is modified from that given by Darwin and Acton. (Darwin, Francis, and Acton, E. H. 
Practical Physiology of Plants, ed. 3, p. 68. Cambridge, [Eng.], 1901.) 
2 Ridgway, Robert. Op. cit. 
