Plant Breeding. 279 



divergent lines. Let us suppose the variation marked i 

 to be the nearest the ideal form. The plants grown 

 from i will again be quite variable in the second gen- 



FIG. 173. Diagram illustrating the selection of seedlings from 

 a cross. 



eration I, but probably less so than in the first genera- 

 tion. No plants of the second generation may be nearer 

 the ideal type than those of the first generation, but 

 we select the plant nearest to our ideal, and plant the 

 seeds from this. Each succeeding generation may be 

 expected to produce less of variability than the one 

 before it. By and by, we may hope to secure a form 

 that approaches our ideal and comes tolerably true 

 from seed. 



445. Planting with Reference to Chance Crossings. 

 Many valuable varieties have unquestionably arisen 

 from accidental crosses between plants of different va- 

 rieties that chanced to be growing in proximity. Profit- 

 ing by this hint, varieties are sometimes planted near to- 

 gether to favor self-crossing, a practice to be encouraged. 



446. Those Who Improve Plants are True Bene- 

 factors. He who produces fruits or flowers for others 

 works a transient good. But he who produces a variety 

 of fruit or flower that is superior to any now known 

 confers upon his race a permanent good. Until the 

 introduction of the Wilson strawberry, the markets of 

 our country were not supplied with this delicious and 



