HISTORY AND SCOPE OF PLANT PATHOLOGY 157 



German investigator and the German cultivator became the fore- 

 most promoters of the science and practice of plant pathology, and 

 maintained the supremacy almost, if not quite, to the present time. 



Beside Kiihn's admirable work issued in 1858, and also a dozen 

 or so small handbooks showing the popular interest, two especially 

 notable works, covering the whole range of the subject as then 

 understood, appeared during this trental period. They were by 

 Sorauer, director of the experiment station at Proskan in Silesia, 

 issued in 1874 and enlarged and improved in 1886, and by Frank, 

 of the University of Leipzig, issued in 1880, both authors after- 

 ward continuing their labors in Berlin. The two works are essentially 

 alike in the division of the topics, except that Frank devotes over 

 a hundred pages to harmful insects, while Sorauer, like most plant 

 pathologist s of the present time, leaves the consideration of insects 

 almost wholly to the entomologist. Disregarding the chapter on 

 insects, both authors devote approximately one half of their space 

 to parasitic fungi, one third to external influences, such as unfavor- 

 able conditions of soil, moisture, air, and food-supply, and the 

 remaining one sixth to wounds and galls. There is no need to go 

 into detail regarding these works; their essential features have been 

 preserved in all general treatises up to the present time, and are 

 familiar to every one having some acquaintance with the subject. 



At the beginning of the ninth decade of the nineteenth century 

 plant pathology was a subject for scholars and for those who wished 

 to know the reason for things, but it had no great economic im- 

 portance. It taught many useful matters, but only in a small way. 

 The part pertaining to parasitic growths was an adjunct of my- 

 cology, that arising from non-parasitic causes was an adjunct of 

 plant physiology, and that having to do with wounds and galls 

 was an adjunct of plant anatomy. But as a unified and independent 

 science it had little standing. To-day shows a great change. There is 

 such a vigorous growth in so many directions that as a science 

 it seems unsettled and ill-balanced, but its merit as an important 

 and vital part of useful knowledge has been recognized. It has 

 become a utilitarian science of vast possibilities. Like the subject 

 of electricity, which not long since was a department of physics of 

 only moderate prominence, it has felt the energizing effect of a 

 demand to help in forwarding the great economic enterprises of the 

 times, which are the foundations of commerce. In the early days 

 plant pathology was developed by botanists who had special love 

 for the subject, working at such odd times as their regular duties 

 permitted. To-day it has its organized and independent workers, 



beobachten und den naturgesetzlichen Zusammenhang der Erscheinungen richtig 

 auffassen lernen, die wahre Frucht naturwissenschaftlicher Studien ist. Klihn, 

 Die Krankheiten der Kulturgewachse , Berlin, 1858. 



