40 HISTORY OF PHYTOPATHOLOGY 



book shows in its detailing of facts and observations the 

 marked influence of the mycologic discoveries of his age. 

 Brilliant man though he was, he failed to understand 

 their true significance and sought to explain them with 

 the philosophy of Zallinger and his school of the 18th 

 century. 



Summarizing the characteristic features of the Unger- 

 ian period, we see that : (1) phytopathologic thought 

 was distinctly physiologic, with a marked tendency 

 toward the mycologic near the end of the period; (2) 

 the basis of classification of plant diseases was etiologic, 

 that, too, in spite of the fact that pathologists would 

 not admit the causal relation of the associated fungi; 

 (3) the influence of the practical gardener on the phyto- 

 pathologic writings of the period was overshadowed by 

 the researches and activity of scientists; (4) the influence 

 of human medicine was still strongly marked; (5) the 

 cause of disease in plants was held to be autogenetic. 

 Increasing observations of the very general association 

 of fungi with disease lesions was constantly raising the 

 question whether these must not be the cause rather 

 than the result of the diseased condition. 



This was the transition period from old, long held, 

 and firmly rooted beliefs and theories with respect to 

 plant diseases to the modern ideas and point of view. 



