66 The Potatoe Plague. 



ground, in which it was easy to trace the progress of the 

 disease, from their being white and nearly transparent. 

 Wherever the stalk was curled, I found the sets diseased. In 

 .^some cases the disease carried the day, and the set reaching 

 ;an advanced stage of decomposition, and the stalks below 

 ground becoming quite brown, the tops died away. In a 

 subsequent season ( 1844) most of the sets attacked perished ; 

 but on this occasion a great majority of the plants threw 

 out strong roots, and finding an abundant supply of food, 

 maintained a constant struggle with the disease, and event- 

 ually yielded a good half crop. 



The experience of this season convinced me that curl, dry 

 rot and wet rot, are one and the same complaint ; that curl is 

 a mild attack of the disease, which, when violent, destroys 

 the set before it can germinate ; and that it assumes the form 

 of dry or wet rot according to the degree of moisture of the 

 soil or season. I have repeatedly seen potatoes affected with 

 dry rot, in a few days assume appearances by which wet rot 

 is usually described; and this change was evidently attrib- 

 utable to heavy rains which had fallen in the interval. 



1841. As I still considered the red potatoes above-men- 

 tioned to be good kinds, and that the occurrence of curl was 

 accidental, I determined to give one of them another trial ; 

 and accordingly, I planted about an acre and a half with sets 

 from the crop of 1840, which had suffered so much from curl. 

 They were planted as late as the 8th of June, the weather 

 dry and unfavorable ; yet in spite of these disadvantages they 

 came " up well, grew luxuriantly, and produced an excellent 

 crop. Side by side with these potatoes two other kinds were 

 grown ; one a black kidney, a very superior potatoe for the 

 table, the other a cattle potatoe. These were bought sets, 

 nor do I know how they had been previously treated. Both, 

 however, were failing crops. The experience of this year 

 was valuable, running directly counter to what has been so 



