1882.] FUNGI INJURIOUS TO VEGETATION. 187 



undergo modifications and form varieties just the same as the 

 higher kinds of vegetation do, and if we can create new varie- 

 ties of grain, why may not new varieties of fungus be also 

 created to prey upon that grain ? They both are formed in 

 obedience to the same natural laws, and I have no doubt that 

 that is entirely possible. But as a matter of fact, wherever 

 we have got a variety of grain, or of potatoes, that seemed 

 for a time proof, or partially proof, against parasitic dis- 

 eases, we have found that by .the cultivation of that vari- 

 ety in regions where other varieties were cultivated that 

 had the disease, it in turn became diseased. I think tliere is 

 no hope of any permanent salvation in that way, but very fre- 

 quently there may be partial help by tlie introduction of a new 

 variety which is less liable to the disease. 



Mr. Wakeman, of Westport. Can we kill this smut that 

 comes into our onion crop by cultivating the ground with dif- 

 ferent crops after it comes in? If I am not mistaken, the 

 lecturer stated in his address that it could be killed by culti- 

 vating the ground three or four years. 



The Chairman. I think a fact which the chair can state 

 in reference to the gentleman who makes this inquiry may be 

 interesting. I met him accidentally at his place a few weeks 

 since, and on my asking him how many onions he had raised 

 this year, he informed me twenty-six hundred barrels. 



Mr. Halsted. I look upon the spores of this onion smut 

 in the soil just the same as I do on seed in the soil. Seeds 

 have a certain length of vitality. They will exist in a dor- 

 mant slate for a certain length of time, varying with the 

 different species, and then the life passes away ; it may be 

 one year, five years, or twenty years. Now, in regard to the 

 spores of the onion smut, they have a certain length of life in 

 the spore state ; if they do not come to the conditions of 

 growth within that time, they die. I think that we can, by 

 not growing onions upon land infested with onion smut for a 

 certain length of time, bring the land back to its normal state 

 through the death of the onion smut spores. 



Prof. Brewer. I had something to do with the beginning 

 of this onion smut discussion, when it was brought up before 



