302 APPLICATION OF PRINCIPLES. 



produce is likewise large and vigorous, and supera- 

 bundant in quantity. Innumerable roots are thrown 

 out from the incised edges of these plants ; they con- 

 sequently receive a greater abundance of nourishment, 

 which occasions their luxuriant growth, causes them 

 to yield not only a more than ordinary crop of seed, 

 but also of a superior quality. (Hbrt. Trans., v. 517.) 

 The operation is performed at the beginning of the 

 dry season. 



Besides " roguing out" (i. e. eradicating) &11 indivi- 

 duals having the slightest appearance of degeneracy 

 from among the plants intended for seed, care must 

 be taken that the crop is so far from any other of a 

 similar kind as to incur no risk of being spoiled by the 

 intermixture of its pollen (88). This substance is 

 conveyed to considerable distances by wind and in.- 

 sects ; and it is scarcely possible to be secure from its 

 influence, if similar crops are cultivated within some 

 miles of each other ; whence we find certain villages, 

 in different parts of Europe, celebrated for the purity 

 of the seed of particular varieties ; this usually happens 

 in consequence of the villagers cultivating that 

 variety and no other, as happens at Castelnaudary 

 with Beet, at Altringham with the Carrot, and in 

 Norfolk with different kinds of Turnip. 



It is, however, to be observed, that the deteriora- 

 tion of seed by bastardising happens to a greater 

 extent to single plants than to large masses of them ; 

 and it seldom happens that good seed can be saved 

 in a garden, or near gardens, from a single indivi- 

 dual. Solitary specimens of the Turnip, the Cauli- 



