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L. R. JONES 
due to the fact that our methods, ideals and leadership have come 
directly from botanical circles. Now that these relations are becoming 
less intimate, the responsibility rests upon both parties to see that by 
conscious effort we keep in closest touch; that the dangers of mutual 
loss from segregation be minimized to the utmost. 
I have chosen the combination title, Problems and Progress, 
because of the necessary relationship of these two ideas. There may, 
indeed, be difference of opinion as to the relative stage of scientific 
progress in plant pathology, as compared with other branches of 
botany. There must, however, be general agreement as to the 
relatively great increase in activity in this field in the last two decades. 
Activity is the gage of life, and fullness of life should be the best 
criterion of progress. But we all recognize that whether or not 
activity or life in any scientific field does measure progress depends 
upon whether or not action is directed toward the solution of funda- 
mental problems. 
Let us with this in mind review the progress in phytopathology, 
trying to define and delimit some of the chief problems as they have 
successively arisen and to decide in how far they have been solved. 
II. The Problem of Parasitism 
Practical-minded men have faced the problems of disease in plants 
since plant culture began and those more scientifically minded have, 
of course, speculated or investigated in the matter. But it will 
profit us little to go back much more than a century for inquiry into 
either their definition of the problems or their progress in the solution. 
When Count Re, of Italy (1807),^ following the lead of the Tyrolese 
von Zallinger (1773), attempted an account of what was known about 
plant diseases, practical or scientific, the result was largely barren 
because he had no conception of the meaning of parasitism. Little 
was known about the fungi and less about their host relations. 
Schweinitz, Persoon and Fries soon laid the secure foundations for 
mycological nomenclature and species descriptions, secure because 
based on keen observations and critical comparisons. But they had 
no concern with plant pathology and their contemporaries who had 
were star-gazing with the nature philosophers. Thus Count Re's 
3 Re, Fillipo. Saggio teorico pratico sulle malattie delle piante. Veneziae. 
1807. An English translation was published in Gardiner's Chronicle, 1849, p. 228. 
