238 
P. C. VAN DER WOLK, 
second. Then it is worthy of observation that the two external layers are 
of a dark red colour while the two inner layers are rose coloured. 
The rhizomorphes as well as the coremies are very brittle. They 
break off in the hand like glass. 
Fig. 6 is the longitudinal section of such a coremium. The deviating 
structure of the rhizomorph is immediately striking. The pith-mycelium 
threads do not run parallel to each other: they are more or less twined 
over each other. The “skin” is of simpler construction than that of the 
rhizomorphes. The pseudoparenchyma cells have here the width of normal 
mycelium threads. 
The real conidiophores are threads, which are divided into irregular 
septa. Each of these threads bears at its extremity one very small oval 
conidium. The conidia thus do not become separated into chains. Each 
general “fruit-stalk” (coremium) constantly possesses but one knob; 
between the conidia and the conidia-bearing threads a yellow slimy 
substance is found, which give the typical slimy character to the knobs 
of the Stilbella-syecies in general. 
* * 
* 
2. A single word now concerning the Ascobolus-lrwit form of this 
mould. There is nothing very interesting about it to say here, since it 
corresponds to the usual type. Fig. 7 gives a section which sufficiently 
speaks for itself. The diameter of the “hat’’ is 3 mm; this is of a green 
colour, produced by a green pigment of slimy consistence which 
is present in the asci. Fig. 8 exhibits some of the branchless as 
well as of the branched paraphyses which, in very large number, are 
prominent far above the asci, just as we have already seen in fig. 7. The 
asco-spores are aparently brown. Their microscopical appearance is shown 
in fig. 9; they possess dark brown warty-processes, which run longitudi¬ 
nally over the spores. 
* * 
* 
3. As already recorded in the first paragraph the Ascobolus and the 
rhizomorphes originate from the cotyles which have become a yellow pulp 
inside the seed-skin. It is remarkable that also already in this cotyle- 
pulp the mycelium threads have united in skeins and that these skeins 
then penetrate the seed-skin and there gives existence to the rhizomorphes 
or the Ascobolus . These skeins are by very careful preparation in some 
cases to be distinguished by a silken gloss by which they contrast with 
the yellow of the cream-coloured pulp. Fig. 10 gives a representation of 
such a preparation. The original mycelium-skein is divided into four. 
The two inmost skeins form the Ascobolus bodies, while the two outer 
skeins give life to the rhizomorphes of the Rhizostilbella fruit form. 
* * 
* 
4. We have still to describe the third form of habitus of this re¬ 
markable mould. 
In the first place the discovery of our mould is a result of exhaus¬ 
tive enquiry after a much dreaded “Sclerotium disease” of various culture 
plants. It is a disease which occurs in our Institute for Plantbreeding 
at Buitenzorg, most severely with Voandzeia and Avachis cultivations, 
and is then also very harmful. 
