Dec. 3, 1917 
Podblight of Lima Bean 
493 
the medium. At the end of 9 days three dark bodies, which were at that time thought 
to be pycnidia, and which probably were sterile ones, were developed. These cul¬ 
tures were kept under observation for 72 days, and no more pycnidia and no spores 
were found. 
Irish potato agar. —There was a visible vegetative growth in two days which 
continued to increase for about one week. A few scattered pycnidia appeared in all 
tubes but one. These were kept under observation for 72 days, and no spores or 
stylospores were ever produced. 
Beep agar. —A rapid vegetative growth during the first seven days of growth. 
Thereafter the hyphae became fluffy and cottony. No pycnidia were formed in any 
of the tubes during the whole course of the experiment. 
Corn-mEae agar. —Growth was not visible in two days, but in four days the 
hyphae had spread over an area % inch in diameter. In six days dark specks appeared 
which later developed into mature pycnidia. At the end of 13 days the slimy white, 
creamy masses began to exude from the pycnidia. These cultures were frequently 
examined thereafter for stylospores, but none were found until after 34 days, when 
they appeared in great abundance. When stylospores and pycnospores are both 
produced, the former always appear after, and never before, the production of the 
latter. 
Cooked rice. —Rice has proved to be a good medium for the growth of this organ¬ 
ism. Hyphae were conspicuous and pycnidia began to form in 4 days. From that 
time the pycnidia increased in number and spores began to exude in 7 days. A 
heavy, black stromatic mass, in which the pycnidia were embedded, was formed. 
As the medium dried out, these stromatic masses were left as conspicuous domelike 
projections over the surface of the medium. The pycnospores were exuded in slimy, 
yellowish, viscid masses in such quantities as to flow over the top of the stroma and 
mostly to cover the surface of the medium. Stylospores were found sparingly in 22 
days and abundantly in 34 days. 
Cooked corn meat.*— Com meal was found to be one of the best media for this and 
other closely related fungi, such as Phomopsis vexans , Plenodomus destruens , and 
Diaporthe batatatis. In 5 days the hyphae covered most of the surface of the com 
meal in 100-c. c. flasks, and pycnidia began to form. The pycnidia were produced 
in great numbers in a more or less well-developed stroma which bore characteristics 
similar to those on rice. The small slimy droplets containing pycnospores were 
first noticed at the end of 13 days. The slimy exudate increased in amount until 
the droplets became quite large and flowed over the sides of the stroma, eventually 
covering nearly the whole surface of the medium. The stroma and pycnidia were 
dark on top and somewhat raised above the surface of the medium. As the com meal 
dried out, the surface became more or less crusty and rugose. Stylospores were found 
for the first time at the end of 22 days. 
* Potato cylinders. —On this medium abundant mycelium was produced. A 
cottony, white growth covered one-third of the potato slant in two days and com¬ 
pletely in four days. In five days incipient pycnidia were seen which later developed 
into a more or less stromatic mass. These masses were at first whitish on top, but 
later turned darker. In 22 days pycnospores were exuding slightly, and stylospores 
were present. At the end of 34 days the stylospores had become more abundant than 
on any other medium; the pycnospores, on the other hand, were relatively few. 
Stems or meeieotus alba. —This medium, everything considered, is the best 
of any so far used. It gives a maximum amount of spores with a minimum of mycelium. 
There were no signs of growth in two days, but in five days numerous pycnidia began 
to form, and these soon became conspicuous as black specks studding the surface of 
the stems. The beaks were comparatively long and conspicuous. In one week 
under optimum conditions the viscid, creamy droplets in which the spores are em- 
