7 
as tlie conclusion I have reached as to the morphological value of smut 
spores and as to the natural position of the smut fungi in the system of 
fungi, will be omitted here because they possess a strictly botanical sci¬ 
entific value, but do not directly contribute to the understanding of smut 
diseases, and their propagation, subjects now specially in question. 
From the ease and luxuriance with which these cultivated parasites, 
vegetated and fructified in the nutrient solutions, with most abundant 
increase of their germ cells in just the same way as any other fungous 
forms occurring in nature as saprophytes, the conclusion followed 
almost of itself that smut fungi can also vegetate in nature on dead 
substrata like all other saprophytes, and that, although invisible to 
the naked eye, they here run through just the same forms as were found 
in the nutrient solutions and have just been described. This conclusion 
found still further support in the fact that I had used as nutrient solu¬ 
tions and nutrient substrata for the smut fungi the entire series of 
media, the composition and compounding of which I had given in detail 
in my Culture Methods for the Investigation of Fungi and had ascertained 
as suitable for the cultivation of saprophytic fungi, especially extracts 
from the fresh dung of our domestic animals, in which the development 
of the smut fungi took place with the same ease as all other saprophy¬ 
tes which were cultivated therein. The wide-spread occurrence of the 
most various yeast conidia in the dung of herbivorous animals, conidia 
which are in no way different from those of the investigated smut fungi, 
was in accord with this conclusion, and further experiments by sowing 
smut spores in fresh dung not too wet proved directly the increase of 
the germs in the fresh dung substances of the earth. Finally, the long 
known and uniform statements of husbandmen that their grain was 
especially subject to smut when they had impregnated the field with 
fresh dung found its equally simple and natural explanation in the now 
actually established increase of smut germs in the fresh dung. 
Instead of smut spores almost incapable of germination in water, e. 
g., corn smut; instead of only scattering and rudimentary spore germina¬ 
tions in mere water, e. g ., oat smut, from the activity of which, according 
to the knowledge of the time, the occurrence qf smut and the spread 
of smut diseases could only be derived, there was now brought to light 
through the new discoveries and their consequences, an entirely new 
and rich vegetative condition of smut fungi. This made the question 
not one of exclusive parasites and their exclusive development on 
the host plants, but revealed, as it were, a most productive center of in¬ 
fection, outside of the host plants, for the propagation of smut diseases; 
a center of infection in which are operative not the few weak germs of 
water germination but an abundance of conidia capable of vigorous 
germination—conidia which can grow out easily into long germ-tubes 
and reach and attack the host plants. 
0 
However extremely probable or wholly self-evident it may now seem 
to have been from the beginning that germs of smut fungi, developed 
