- 14 - 



The above mentioned figures prove, that the farther 

 removed the plants were frorn the original source of 

 infection, the smaller became the number of infected 

 plants in each row. 



On May 20 (/i an experiment was started with two 

 rows, wich lay parallel to each other, consisting each 

 of forty plants while at one end of each row a dis- 

 eased plant was purposely put in. 



In row A beginning with the diseased plant, the 

 uneven plants were only touched, viz. plants numbers 

 ], 3, 5 etc— 39. ; 



in row B also beginning with the diseased plant, one 

 plant at every three plants was touched, viz. plants 

 numbers 1, 5, 9 etc— 37. 



From May 20"' till June l s( the plants in question were 

 touched only three times and yet all the touched plants 

 in both rows showed already on June 2 nd the well 

 known symptoms of the diseaseina very pronounced form, 



Similar experiments were repeated many times and 

 varied in différent ways, as regards the number of plants 

 that were touched and omitted and always with the 

 resuit, that all touched plants without exception became 

 diseased, while the untouched ones showed only later on 

 by exception the symptoms of the disease. Twice during 

 my experiments a plant was found which notwithstan- 

 ding repeated touching with infected Angers dit not yield 

 to the disease. 



The power of résistance was probably so strongly 

 developed in this case, that slightly touching had no 

 bad conséquences. It must be mentioned, that thèse 

 plants, which were little predisposed to the disease were 

 of délicate structure in both cases. 



The conclusion to which we can now come is not at 

 all doubtfull. 



