236 
P. C. VAN DER WOLK, 
Organe bei Züchtung auf Invertzucker, wo die Concentration von dieser 
zur Atmung mehr geeigneten Zuckerart größer ist, wenn also in jedem 
Augenblicke mehr davon vorhanden ist. Die Annahme, daß die Ursache 
in irgend einem Entstehungszustande der einfachen Zuckerarten zu suchen 
wäre, scheint mir weniger wahrscheinlich. 
Rhizostilbella rubra (n. gen., n. spec.) a by-fruit 
form of Ascobolus parasiticus ( nov. spec.); and its 
connection with the “Sclerotium disease“ of cer¬ 
tain tropical cultivated plants (Sclerotium omni- 
vorum n. spec.). 
By 
P. C. VAN DER WOLK, Buitenzorg (Java). 
(With 1 col. plate.) 
Since several months I observed a large closed culture-pan in which 
plants and fruits of Voandzeia subterranea were actively decomposing. 
During the first few days since the introduction of the fresh plant-material 
to the culture-pan (as is here in the tropics so constantly seen) everything 
possible of the commoner and also of the less-commoner moulds made 
their appearance in turn on the decaying material. It was an alter¬ 
nate revelation and fading away of every variety of the shades of conidian 
colours; a keen struggle for existence, an ever-renewed pleasure to obser¬ 
ving eyes, and a true source of enjoyment. 
After this display had lasted for a month or so however, the 
“system” of lower moulds was gradually exhibited to the observer in 
broad traits. Then, in this decaying material the circumstances had evi¬ 
dently become untenable even for the most persistent saprophytes; the 
fruits, the stalks, the particles of earth had become as black as pitch, 
slippery and shining, with every sort of putrefactive bacterium, while an 
insupportable stink filled the culture-pan. Then after the first month had 
elapsed, the last mould visible to the naked eye utterly vanished, and 
the host of moulds seemed to have died out for good; a long mouldless 
period ensued. I continued to observe the culture-pan with its aspect of 
death, and finally my zeal flagged a bit, and the pan lay forgotten in a 
corner for two months or more. 
What was my astonishment when one day glancing at the pan I was 
delighted by an unusually beautiful colour effect. Fruits and stalks were 
compactly covered with fiercely-green toadstools of the Ascobolus- type, 
while among this all, fruits, stalks an the pieces of earth were covered 
with fiery-red rhizomorph-like bands, while from these bands themselves 
there sprung a host of “conidium-bearers” (coremia), provided with little 
