2 
attention. Keeping step with further knowledge and experience in 
mycology they are always taken up afresh whenever any new sugges¬ 
tions or new views for further enlightenment open up, and whenever 
new methods of research show new points for attack. 
In this way, then, my researches on the smut fungi and diseases, 
begun about eight years ago, were only the natural continuation of the 
labors of earlier authors; except that they were accompanied by other 
and fresh thoughts and supported by methodical expedients such as 
previously had not found employment, nor, indeed, could find it. They 
were begun after a long stand-still iu observations on smut fungi and 
smut diseases, and when renewed experiments with the worn-out 
thoughts and methods would give no new and substantial results. 
Till my experiments everybody proceeded upon the supposition that 
the fungi existing parasitically in nature found their natural conditions 
of existence only upon their hosts, and therefore that the different smut 
fungi could live and grow only upon the different but definite and re¬ 
stricted host plants, on which they were observed in the open air. Ac¬ 
cordingly it was very evident that experiments and observations must 
be confined to the host plants; that iu order to investigate the connec¬ 
tion of fungus and disease, the fungous germs, found on the host plants, 
consequently the smut spores, must be sowed again upon the host plants 
and their development followed. The idea was so simple and natural 
that candid minds did not suspect the confusion of perception and judg¬ 
ment which this thought naturally carried with it. 
Upon the host plants the smut spores find, first, only moisture for 
their development, consequently they must germinate on the surface of 
the plants just as they germinate in a small drop of water. Now, ger¬ 
mination experiments with smut spores in water have shown most 
convincingly that the spores in many cases, e. </., in corn smut, do not 
germinate 5 that in other cases they germinate only iu small numbers 
and very imperfectly, e. g in oat smut and millet smut. From these 
negative or at least imperfect results of germination in water, which 
results were to be observed in just the same way upon the surface of 
the host plants, the universal distribution of the fungi in question and 
of the smut diseases in grain could be explained only very imperfectly 
or not at all. Nevertheless, these explanations gave satisfaction, the 
rudimentary consistency of facts was regarded as complete, and to no 
mycologist did it occur that any one would succeed in acquiring new 
information or in making a very important advance in the knowledge 
of smut diseases. 
My culture methods for the investigation of fungi, were slowly and 
painfully established and brought to gradual completion during the 
long period of more than sixteen years, and meanwhile put to use, alike 
in the minute schizomycetes and the great mushrooms, in the simplest 
as well as the most highly developed fungous forms, with similar trench¬ 
ant results for knowledge of the developmental history of fungi. These 
