IN THE TROPICS. 
31 
into the germinative capacities of fungus spores, and 
do not doubt that a solution may be found suitable for 
the growth of these forms, which have as yet proved 
resistant to all methods tried. The period of germination 
varies much ; some spores, such as those of the Muco- 
rineæ, form long hyphæ after a few hours, while others 
only show the first phenomena of germination after three 
or four days. According to my experience, spores which 
remain unaltered after a week in the solution usually 
remain permanently in this condition. A certain amount 
of foresight must also be exercised in the choice of spore 
material. A few fungi, especially among the Myxomycètes, 
seem to lose their capacity for germination in a few days, 
and this again may vary in the same species. For instance, 
I found an Ustilago very common in Java on a Polygonum : 
the fresh material only germinated very slowly, while later 
experiments tried in Berlin succeeded admirably. In 
Arcyrea punicea (a Myxomycete), on the other hand, the 
fresh material was preferable, for in the course of only an 
hour and a half after sowing the slide was full of swarm 
spores, while a few months later the results were entirely 
negative, and no efforts would induce germination of the 
spores, which formerly had proved so easily manipulated. 
Other species, again, retained their capacity for germination 
for a long period, but became sluggish, ^.e., their germination 
was later. In many i^scomycetes in particular I frequently 
found that freshly collected material was most satisfactory, 
but that after the lapse of 6-12 months the germination was 
much slower. In the Myxomycètes the spores particularly 
soon lose their capacity for germination. As is well 
known, the growth of the higher plants in the tropics is 
much more rapid than with us. Judging from cultivation 
experiments this is not the case with the fungi, or at any rate 
the germination and the subsequent formation of mycelium 
proceeded, with the same species, just as rapidly in the 
Berlin Institute as in Colombo or in Batavia. It was also 
