364 Essed . — The Surinam Disease. A Condition of Elephantiasis 
probably due to tension in the tissues caused by the huge amount of hyphae 
pushing through to the basal air-spaces and sheaths of the leaves, and to the 
slow disintegration under the influence of the enzymic secretion before or 
during the forming of pegmatia. Under ordinary circumstances, the lining 
of the basal air-spaces of the leaves show a corrugated whitish appearance, 
due to the desiccation and throwing off of the lining cells ; but when the 
fungus is feeding on the banana, and hyphae are running to the air-spaces, 
the process is accelerated and intensified, and the lining becomes a yellowish, 
granulo-caseous substance, due to the breaking away of a large amount of 
hardened yellow slime cells, stimulated by the fungus, in some of which 
spores may be seen to arise. The swelling of the base of the stem proved 
to be brought on by metaplastic changes in the tissues. 
Although the germ tubes of spores were not found actually penetrating 
the rhizome anywhere, it was seen that hyphae were running horizontally 
and moving centripetally not very much below the base of the outermost 
leaves. So it looks very probable that the infection takes place here, where 
the young cells with comparatively thin walls facilitate the entrance of the 
fungus ; then, if the mycelium spreads through the upper peripheral parts 
of the rhizome at first, and if we consider that new buds on the rhizome in 
the most cases arise in the lower underground portion, it is readily explained 
why the propagation of the disease within a c hill * may be checked by care- 
fully removing a diseased member. Moreover, if the mycelium can only 
penetrate the base of the outermost leaves in a comparatively young condition, 
then it will be plain that the chances of infection are very much restricted, 
and it will at once explain why the disease is so slow in spreading. 
Pure cultures were raised in the way followed in isolating the Ust. 
musaeperda. Here, again, the same bacterium appeared on the cultures, 
showing convincingly that this bacterium is an ordinary soil bacterium and 
not pathogenic at all. The young mycelium most strikingly resembled 
that of the Ust. musaeperda , but later on, when the reproductive development 
sets in, the differences become apparent (see Fig. 2). 
Pegmatia. The only difference, but surely not essential, is the rather 
conical shape of the chlamydosporangioid pegmatia. All the other kinds of 
pegmatia are identical with those of the foregoing fungus. 
Spores . The chlamydospores do not differ in their mode of origin and 
their outlines, but they are somewhat smaller, nearly always greenish 
brown. The oidia are about the same. The only essential difference, by 
which also the relation to the Ust. musaeperda is defined, lies in the 
conidia. In the Ust. oedipigera we meet with 1- and 2-cellular, very 
seldom 3-cellular, conidia ; they are plumper and rather sausage-shaped, 
grouped in heads, which are kept together by a drop of hyaline mucilage. 
The branching is the same, but here we find an even greater tendency to 
become verticillate (see Fig. 3). 
