3 
led me, in their further perfection, gradually to results which made the 
difference between fungous forms that maintain themselves as parasites 
on living plants and animals, and such as live only as saprophytes on 
dead organic substances, appear less sharp than, according to the com¬ 
mon state in nature, it was believed to be. I succeeded artificially, 
with my nutrient solutions, in growing fungous forms as luxuriant as 
were to be observed in nature on the host plants, and in some cases 
much more luxuriant, e. g., Peziza ciborioides and P. sclerotiorum , which 
in nature are found living on clover and rape; also, Sphacelia se- 
getum , the fungus of ergot, and many others. This itself led me to 
considerations on the nature and reality of parasitism and on the way 
in which the various parasitic phenomena in nature might come about. 
These observations always led only to the one reasonable conclusion, 
that parasitism can be nothing else than a form of existence which has become 
more or less suited to the fungus according to the length of time, and differ¬ 
ently and specifically adapted to it in each individual case, but which, for 
all that, has become by no means constant. It was only the natural con¬ 
sequence of these trains of thought, based upon observations in nature, 
and upon the results obtained in my culture experiments, to draw this 
conclusion: Even in the most distinctly marked cases of parasitism, in 
which the fungus is found only on given plants or even on particular por¬ 
tions of these, nothing else is before us except the furthest extended phenom¬ 
ena of the same adaptation, which by its more developed form produces 
the outward appearance , as though the natural conditions for the ex¬ 
istence of these parasites were given exclusively in the living substratum, 
consequently in the particular host plants , or special portions of these, and 
as though every other way of life and growth were altogether excluded. 
And by this outward appearance all mycologists were obviously cap¬ 
tivated, until my investigations. No botanist had thought of critically 
examining the essential nature of parasitism, of following out naturally 
the sole possible origin of parasitic phenomena, and of making it clear 
in what way the whole multitude of its variations is simply and natur¬ 
ally subordinate to one unifying thought, a thought which included in it¬ 
self not only the possibility but also the probability that fungi living par asit- 
ically—at least the greater part, if not all of them—can live outside of the 
host plant. 
When, almost ten years ago, I gave publicity to my views on parasitism 
along with my culture methods, and at the same time expressed strong 
confidence that unquestionably it must be possible artificially to culti¬ 
vate most, if not all, parasitic fungi, my views remained not only gen¬ 
erally unconsidered, but were in special cases, in the Botanische Zeitung, 
even scornfully criticised. This circumstance shows, as no other, the 
confused judgment of mycologists upon parasites and parasitism, and 
enables one to measure clearly the difference between the old sterile 
ideas and the new fruitful thoughts. Only this confusion of ideas, 
which must be plain upon considerate reflection, could have prevented 
