386 THE SELF-FERTILIZATION OF PLANTS. 



with their parent varieties, and the editor states, that 

 they were intermediate in character, ' united with that 

 greater vigor of growth, which, it appears, in the vege- 

 table, as in the animal world, is the result of a first 

 cross.' Knight also crossed several varieties of wheat, 

 and he says, 'that in the years 1795 and 1796, when 

 almost the whole crop of corn, in the island, was 

 blighted, the varieties thus obtained, and these only, 

 escaped in this neighborhood, though sown in several 

 different soils and situations.'" 



On page 281, Vol. ii, Animals and Plants, &c, he 

 says: 



"The straw of the Fenton wheat, is remarkably un- 

 equal in height; and, a competent observer believes, 

 that this variety is highly productive, partly because 

 the ears, from being distributed, at various heights, 

 above the ground, are less crowded together." 



Doubtless, to this is due some of the effect; but, it 

 is probable, that, with the inequality in height, there is 

 a diversity in the quality of the different classes of 

 tissues, in the proportion of the chemicals assimilated, 

 and in others of the characters; and, that the fertility 

 arises from the interbreeding of the individuals, which 

 is, under the circumstances, tantamount to crossing. 



It may be asked, by the reader, unacquainted with 

 the motives which govern seed-growers, in their selec- 

 tion; Why, if such great increase in vigor, size, fer- 

 tility, &c., is secured by crossing, is not that process 

 generally resorted to? The reason is, that the im- 

 provement of /the plants is but a secondary considera- 

 tion, with planters. Their first aim is, to secure uni- 

 formity of character, in the individuals of each variety, 

 and this end is frustrated by crossing. Upon a cross, 



