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solely the result of peculiar atmospheric conditions, favorable to the 

 growth and increase of parasitic fungi, how is it that there has not been 

 a similar extensive attack on other species of plants also? The alterna- 

 tives presented by this question are these : — either the parasite of the 

 potatoe requires for its rapid development certain atmospheric conditions, 

 diflfering from those required by the parasites of other plants, or there 

 must be some inherent predisposition in the potatoe plant Avhich has led 

 to this extensive attack of its parasite, and which is not the immediate 

 and exclusive result of atmospheric influences. Want of space will not 

 allow me to enter more fully into this branch of the inquiry. I sent a 

 paper on the growth of fungi to the lamented A. J. Downing, which ap- 

 peared in the Horticulturist for July 1851, and if any one should desire 

 to pursue the inquiry further I would respectfully refer him to it. The 

 question is one of considerable importance to farmers and gardeners, and 

 it has received little attention hitherto. 



Is there any evidence that potatoes generally were not in a healthy 

 condition, previous to the appearance of the present malady ? It has 

 been said there are no data on which to found a conclusion of this nature. 

 At the meeting of an Association for the Advancement of Science, it was 

 said, "debility was supposed to exist," but no proof was given of the 

 existence of debility, and what, it was triumphantly asked "is the proof 

 of debility in a potatoe ? " This betrays a lamentable want of knowledge 

 of the previous history of the potatoe ; and it is requisite that a man 

 should know that history before he can be qualified to see the question 

 in all its bearings, give due weight to facts, or arrive at sound conclu- 

 sions. Formerly the potatoe was considered the most certain of all 

 crops, but it has gradually become, of all crops, one of the most preca- 

 rious and troublesome. Formerly the tubers would bear almost any 

 treatment without injury ; as an old writer observed, it was "a plant, if 

 possible, more tenacious of life than couch grass." Of late years, and 

 before the appearance of the blight, innumerable consultations have been 

 held, experiments made, and essays published, with a view to discover, 

 if possible, how best the tubers can be preserved from premature decay. 

 And yet, we are asked "where are the proofs of debility?" 



I spent a week or two in the Library of the British Museum hunting 

 tliroufrh piles of musty old volumes on farming and gardening for infor- 

 mation respecting the diseases of the potatoe, and more especially whe- 

 ther the blight had ever been experienced before. And I can prove by. 



