BOTANY mi) FLAwT PATnOLCKiY SEMINAR
ember 15* 1951 Joe Hennen
The Early Development of the Idea of the Causal Nature of Fungi in
Relation to Plant Disease*
Io Isaac-Benedict Prevost 1755-1819
A.) His most important contribution to our present way of thinking,
in my opinion, is that through ul    xogical reasoning and experimentation be concluded that the internal parasitic bunt plant was the immediate or direct cause
of the bunt disease of wheat, but he made It aqialiy deer that the parasite
could induce the disease only under certain specific conditions. Later, after
having clearly established these conditions, he spoke of the bunt as the cause.
His usage of the causal idea must be considered carefully by those of us who
wish to make our concepts clear and terminology precise in all fields of endeavor*
Bo) His work showed that the immediate cause of bunt was a micro-
organism* This was the first of its kind brstd on adequate experimentation.
This was the beginning of one of the most bnsic and productive scientific concepts that later became a foundation for fch j more generalized germ theory of
disease.
C*) Prevost was largely self taught* He became a tutor and later a
professor of philosophyo In his early productive lift he devoted himself to
mathematics, later to physics and natural history*
D«) In His memoir on hunt he gavs descriptions of the symptoms of the
disease on wheat as well as thr* microscope details o:f the development of the
«%ont plant* in relation to time, tmperatuxv, toxic e gents, concentration of
spores^ and previous treatment of the spores* His toxicological studies on the
effects of copper form a basis for modern fun^cidal control of plant diseases*,
II» Karl Fxledrich Phillip v*n Martius 1794-1*63
Ao) The Royal Scientific Academy at Kunich called upon Martius to
study the late blight of potato due to the tlestmctive outbreaks of the diseaae
inPfla^ Germany in 1841* He made the firs4/ scientific avuc*y of late blight and
published the first description and figures of rhe  disease and fungus in his
^Die Kartoffel-Epidemie der letsten Jahre oier cie Stokfaule und Rauge der Kar~
toffeln,11 Munich 1842« His results were casaunicated to the Paris academy and
called to the attention of governments and i.grieulturiste. However little heed
was given to the gravity of the situation arid no precautions were taken.
Be) Martius was one of the few professional botanists of this period
to contribute to plant pathology * He had gained muc'i knowledge about plants on
his extensive collecting trip to Brazil (l&i'*~~20)o He contributed much to systematic botany, his work on palms being especially important. He became director
of the botanical garden in Munich and worked cm a system, of plant classification.
in. Miles Joseph Berkeley 1803-1889
A*) Two significant contributions were mad;* by Berkeley to the general
acceptance of the idea of the causal nature of fungi In relation to plant disease*
In his observations on the potato murrain, \j pointing out tne falliciee of others
in their reasoning «^ he showed that the numerous prevailing iasas concerning the
cause of the disease could not be accepted logically* For instance he pointed out
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