273 



contended from the first, that if I am right in my conclusion respecting 

 the degeneracy of the plant as a species, it would not do to depend on the 

 first or second year's seedlings, however healthy they might seem to be; 

 as I said, in 1845, in a letter on the blight, in the London Morning Herald, 

 "it is only by improved culture, judicious selection, and several succes- 

 sive generations that we can have any just grounds for hoping to restore 

 the potatoe to its pristine state of vigor and health if it ever can be ac- 

 complished by this means with these plants." It is a fact observed in 

 America and Europe, that some varieties offer much greater resistance 

 to the disease than others ; now, whether this is owing to a difference in 

 constitutional vigor, or to some idiosyncracy of these varieties, how but 

 by having recourse to seedlings, is their number to be increased, or how 

 are they to be superseded when in the course of time their energy de- 

 clines, or how can we be sure that others may not be obtained by careful 

 and skilful management which will resist the disease better than any we 

 now possess ? In an article on the potatoe by Prof. Lindley, written 

 before tho appearance of the blight, he said, "finally let us point to the 

 immense importance of renewing the vigour of potatoes, by raising new 

 varieties from seed. This has been tried over and over again, and always 

 with some advantage, sometimes with a great deal." 



I may here state my conviction, that when the potatoe has been restored 

 to the highest state of health it is capable of attaining, that specimens of 

 the fungus may be found on plants in some situations, even in the most 

 favorable seasons. I conceive it would be mere quackery to hold out any 

 hope, that botrytis infestans, now that it has established itself in this 

 country and Europe, will be entirely banished, when the general health 

 of the potatoe plant has been restored. We can only infer what may be 

 the future power of the parasite over the potatoe by the data afforded by 

 other plants ; and our knowledge of the causes which induce partial at- 

 tacks of fungi on wheat, turnips, and even plants in a state of nature, 

 forbid the hope that our potatoe crops will ever be entirely exempt from 

 the pest. All that we are justified in expecting is this : that in the most 

 unfavorable seasons we are likely to experience, there will be no such 

 general attack as of late years, and that when local or transitory influ- 

 ences are sufficiently powerful to render certain plants unhealthy, and thus 

 to favor the attack of the parasite, there will not be that rapid decompo- 

 sition of the plants as now, but that the parasite will be confined chiefly 

 to spots on the leaves. In ordinary seasons I anticipate the fungus will 



