772 Fluctuations 



of the extreme individuals have exceptional 

 chances of becoming better nourished than the 

 average of the seeds of the race. Applying the 

 same rule to them, it is easily understood that 

 they will vary, by reason of this better nourish- 

 ment, in a direction corresponding to that of 

 their parent. 



This discussion gives a very simple explana- 

 tion of the acknowledged fact that the seeds of 

 the extremes are in the main the best for the 

 propagation of the race. It does not include 

 however, all the causes for this preferment. 

 Some are of older date and due to previous in- 

 fluences. 



A second point in our discussion is the appre- 

 ciation of the fact that a single individual 

 may be chosen to gather the seed from, and that 

 these seeds, and the young plants they yield, are 

 as a rule, numerous. Hence it follows that we 

 are to compare their average and their ex- 

 tremes with the qualities of the parents. Both 

 are of practical as well as of theoretical inter- 

 est. The average of the progeny is to be con- 

 sidered as the chief result of the selection in 

 the previous generation, while the extremes, at 

 least those which depart in the same direction, 

 are obviously the means of further improve- 

 ment of the race. 



Thus our discussion should be divided into 



