164 PLANT PATHOLOGY 



In the long list of indebtedness held against plant pathology by 

 various sciences, physiology stands foremost with the largest ac- 

 count, a condition fully recognized as early as the days of A. P. 

 de Candolle, and especially emphasized at the present time. But 

 in close succession follow mycology, anatomy, bacteriology, chem- 

 istry, cytology, physics, toxicology, phylogeny, and other subjects 

 in diminishing degree. That the science is largely in an uncrystal- 

 lized condition, when looked at from our new points of view, is prob- 

 ably the reason why no handbook written from the modern stand- 

 point and covering the whole subject has appeared since 1880, 

 with the exception of the small, introductory, but highly luminous 

 work by Marshall Ward, issued in 1891. 



I trust that in this cursory presentation of the history and scope 

 of the science of plant pathology I have made clear some of the 

 lights and shadows that give interest to a subject of great economic 

 and scientific importance. 



