474 



THE POPULAR SCIENCE MONTHLY 



Ancient 



Medieval 





1700 



1650 



1870 



1890 



1900 



1910 













— 



— 



— 



— 



— 



— 



— 









Cereal Rusts 





Weather Influence Efc 





































Canker (Nectna) 

































Timber Rots 























— 





Pear & Apple Blqht 













— 











1 — \ 1 k A 1 1 





























Powdery Mildew 



















































Lrqot 





Club Root 









— 





— 







Potato Bliaht 

























Apple Scab 





— 









[= 













Apple Rust 



















Plum Knot 

 Alfalfa Pseudopezizose 











































RoseActinonemose 





Grape Rasmoparose 









































\3\ Upc DIUC-r\ nUI 



Apple Glomerellose 





















Table I 



Table I (Continued) 



Ancient 



Medieval 



I7(|)0 I 1850 



1870 



1890 



1900 



<: 



1910 



] Yellows, Peach 



Drupe Brown Rot 



Pome Brown Rot 



Onion 5mut 



Tobacco Mosaic 



5cerotiniose 



Peach Curl 



Bean Pod Spot 



Pythiose 



BotrYose 



RaspberryAnthraaiose 



Cotton Wilt 



Baallose of Solonaceae 



Cotton Anthracnose 



Potato Scab 



Ozoniose 



Cruaferae, Pseudomonose 



Apple Blotch 



Table I. Showing Advance in Knowledge begakding some of the Chief 

 Plant Diseases. The broken upper line indicates vague or indefinite knowledge ; the 

 solid line definite knowledge. The lower broken line indicates partial but unsatisfac- 

 tory knowledge concerning treatment ; the solid line the possession of facts sufficient 

 for satisfactory treatment. 



