SPORES OF MILDEW. 233 



refuge ? At the lowest limit of the vegetable kingdom, some 

 would say below the lowest limits, is a large group of very 

 minute beings, called " Bacteria." They are verj^ small ; they 

 are found everywhere ; their study taxes the highest jjowers 

 of the first scientific men. It will be a long time before the sci- 

 entific world knows much about them, and longer still before 

 the public do. What a paradise for quacks ! Without being 

 a prophet, it will be safe to predict, that, within the next ten 

 years, the agriculturist will have to listen to an immense 

 amount of nonsense about the harm these small bodies do, and 

 the diseases they cause. In the mean while, let us not under- 

 rate the harm done by fungi, while deprecating all attempts 

 to make them responsible for every disease which may make 

 its appearance ; and here, as in other things, a little knowledge 

 is a dangerous thing, for it is only by cautious and careful 

 research that we reach results which are really valuable, 

 either scientifically or for practical application. 



Mr. Flint. I find this question in the question-box : Is 

 mildew-seed in the air, or in the land ? I would like to have 

 Professor Farlow make some statement, if he has any thing 

 to say upon that question. 



Professor Faelow. It is in both. This fungus, you know, 

 has two kinds of seeds, cr spores. The seeds that are found 

 on the under surface of the leaf drop off on the ground, or 

 at least into the air, and can be carried about by the wind. 

 The other seeds are found in the tissue of the leaves ; and as 

 the leaves fall off, and fall upon each other, of course there 

 is quite a respectably thick layer of leaves upon the ground. 

 These are covered by snow ; the leaves rot ; and these spores 

 will be left upon or in the ground, because they will be more 

 or less buried. 



Mr. Hills of Arlington. I proposed that question. The 

 fact is, I have raised considerable lettuce, and I am troubled 

 with mildew. I have noticed, that, when I went on to new 

 lands, I was not troubled with it. I have been to considera- 

 ble expense in moving my fences, so as to enclose land where 

 lettuce had not been gro^vn ; and some men in the same busi- 

 ness think it was foolish to do so. They say the spores are 

 in the air. 



Professor Farlow. Some of these seeds will be killed in 



30 



