66 On the prevention of the Curl in the Potatoe. 



scarcely accede to this hypothesis, because I do not think it 

 probable that a plant, which is a native of Virginia, can be 

 over-ripened in the climate of Scotland ; and because those 

 varieties, which never afford either blossoms or seeds, have, 

 in my garden, been quite as subject to that disease as others. 

 Mr. Dickson has stated the curious fact (and I do not en- 

 tertain the slightest doubt of his perfect correctness), that a 

 cutting taken from the extremity, which is most firm and fa- 

 rinaceous, of a long, or kidney-shaped Potatoe, will afford 

 diseased plants, whilst another cutting, taken from the oppo- 

 site end of the same Potatoe, will produce perfectly healthy 

 plants ; but I do not attribute this to the greater maturity of 

 the buds at the extremity, than at the opposite end, for those 

 nearest the parent plant are really the oldest, the tuber being 

 formed by a branch, which has expanded itself laterally, 

 instead of having extended itself longitudinally. Its buds are 

 in consequence arranged as they would have been upon the 

 elongated branch ; and every tuber, in its incipient state of 

 formation, will extend itself into a branch, as I have shown in 

 the Philosophical Transactions for 1809,* provided the plant, 

 to which it belongs, be cut off close to the ground, and the 

 current of ascending sap be in consequence diverted into, 

 and through the tubers. Mr. Dickson, and myself, however, 

 perfectly agree that a tuber, or part of one, which is soft 

 and aqueous, affords a better plant than one which is firm and 

 farinaceous ; and the trifling difference of opinion between 

 us, being purely hypothetical, is of no importance. 



I observed that the crops of Potatoes, which I raised from 

 the late ripened tubers above-mentioned, were not quite so 



* Page If 4. 



