6 
tion of another still open question , the sprout-fungus or yeast question. It 
could only be considered as a simple matter of time when, through the 
spore culture of the remaining higher fungi, further and supplementary 
proof would be brought as to which forms among these fungi include 
in their course of development the still remaining sprout fungi which 
do not belong to the various smut fungi. The investigations in this 
direction have meanwhile, it may be mentioned in passing, already led 
to the most far-reaching results in the most diverse Ascomycetes and 
Basidiomycetes. 
Aside now from the forms of smut fungi which, like Tilletia , produce 
large mycelia with conidiain nutrient solutions, and aside further from 
the forms which, like TJstilago carbo , U. cruenta , and TJ. rnaydis , pro¬ 
duce conidia in endless sprouting in yeast form, there are still other 
forms which produce conidia on the conidiophores of the germinating smut 
spores (the promycelia), which do not sprout directly , but always first grow 
out again into new promycelia until the conidia sprouting begins anew on 
these. Here belong, for example, TJstilago longissima on Poa aquatica , 
and U. grandis on Phragmites communis , with many-celled promycelia, 
and TJ. bromivora on Bromus secalinus, with typical two-celled promy¬ 
celia. 
Finally, forms were also discovered, as for example TJstilago Grameri 
on Setaria , TJ. liypodytes on Elymus arenarius , etc., the smut spores of 
which , germinating in nutrient solutions, produce no conidia , but only sterile 
germ tubes , that grow into richly-branched mycelia , which in turn also re¬ 
main free from conidia. Here afterward the single threads pushed 
far out, stolou-like, and abjointing, constituted, in place of the absent 
conidia, the richly increased mass of germs present in the nutrient solu¬ 
tions. 
In short, these are the most essential results which the cultivation of 
the spores of the various smut fungi in artificial substrata, in nutrient 
solutions (therefore outside of the host plants, where they are found in 
nature) had given four years ago. The number of forms the cultivation 
of which was tried in nutrient solutions then amounted to more than 
twenty. As supplementary, I have extended the cultivation to an ad¬ 
ditional twenty forms, some of which brought to light similar peculiari¬ 
ties as in the first series, e. g ., in the genera Schizoriella and Tolypospo- 
rium , which produce sprout-conidia; while others yielded new and sup¬ 
plementary facts, the special communication of which however, * as well 
* Only incidentally I will state for example that the genns JSJeovossia and species of 
Urocystis behaved the same as Tilletia. Of the recently investigated forms of the old 
genus Uslilayo , which in its present extent is wholly untenable, a number behaved 
the same as Ustilago carbo, and produced sprout-conidia of various shapes; others, 
e. g., TJ. caricis, TJ. subinclusa, and TJ. echinata , germinated in a specific manner with 
the production of little conidiophores bearing air conidia similar to Peronospora. Us- 
iilago Vaillantii agreed with the type of U. longissima; TJ. hordei, a recently distin¬ 
guished form on Ilordgacew, produced large, sterile, e. g., conidia-free, mycelia, like TJ. 
Crameri , etc. 
