226 BOARD OF AGRICULTURE. [Jan., 



was free from it, or if I could get a crop that I could carry 

 through to a later time in the season with less spraying than 

 other native varieties. I found, however, that I had it, and I 

 explained it on the ground that it was carried in by the potato 

 bugs. The disease is a peculiar one. You may have a crop, 

 which so far as a careful examination shows is absolutely free 

 from spores. Then, if you have a spell of wet weather come 

 on, and a little drop of moisture gather upon a leaf, a spore 

 will germinate in that moisture, and in a few hours the fungus 

 will penetrate into the leaf. After it gets into the leaf, it grows 

 with the weather, especially if the weather is muggy, and 

 damp. If the weather is dry it comes to a standstill and does 

 not progress. 



The President. I would like to ask Prof. Clinton if he 

 does not consider that the difference in the two lots of ground, 

 one where potatoes had previously been raised, and the other 

 where they had not, was a sufficient reason for there being a 

 difference in the progress of the blight ? 



Prof. Clinton, I am not quite prepared to say that. 



Mr. Beach. The condition of the soil and the method of 

 treatment was very much the same, but the area where the 

 blight appeared, and where we suffered the most from the 

 ravages of it, did not have potatoes upon it last year. It had 

 them two years ago. I know it had no potatoes last year, but 

 I want to make it clear that it was the very same soil, and the 

 crop received the same treatment. I could see no reason why 

 there should be any difference between the two parts of the 

 field except that the blight spores had Hved over for two 

 years. 



The President. Don't you think that virgin soil where 

 potatoes had never been raised before is not as likely to pro- 

 duce the disease? 



Mr. Beach. I don't see why that should make any dif- 

 ference with the blight on the leaves. The spores of the blight 

 may be in the ground that has been affected, and that is what 



