CH. VIII.] THE DISEASES OF PLANTS. 257 



that had been kept warm and moist, and from which 

 the shoots, after attaining a length of six inches, 

 had been thrice removed. No. 3. Twenty sets that 

 had been kept warm and moist for about half the 

 time that No. 2 Had, and from which the shoots, 

 three, inches in length, had been removed only twice. 



All the sets were planted the same morning, each 

 exactly six inches below the smface, and each with 

 an unsprouted eye upwards. The spring was genial. 



Of No. 1, nineteen plants came up. The twen- 

 tieth seemed to have been removed by an accident. 

 Of the mneteen not one was curled. The produce 

 a ftdl average crop. 



Of No. 2, all came up, but from ten to fourteen 

 days later than those of No. 1, and three of the 

 plants sixteen days later. Fourteen of the plants 

 were cm-led. 



Of No. 3, all came up, but from ten to fourteen 

 days later than those of No. 1. Fom' plants were 

 as severely curled as those in No. 2, eight were less 

 so, and the remainder not at all ; but of these the 

 produce was below an average, and a full fortnight 

 later in ripening. 



Dickson, Crichton, Knight^, and others have found, 

 that tubers, taken up before they are fully ripened, 

 produce plants not so liable to the curl as those 



" Caledonian Hort. Mem., Horticultural Trans,, Loudon's Gar- 

 dener's Mag., &c. 



S 



