788 Fluctuations 



nection with the detailed pedigree-cultures. It 

 is the question as to what is to be expected from 

 a continuation of long-continued selection. 

 Would it be possible to obtain any imaginable 

 deviation from the original type, and to reach 

 independency from further selection? This 

 point has not until now attracted any practical 

 interest, and from a practical point of view and 

 within the limits of ordinary cultures, it seems 

 impossible to obtain a positive answer. But 

 in the theoretical discussion of the theory of 

 descent it has become of the highest importance, 

 and therefore requires a separate treatment, 

 which will be reserved for the next lecture. 



Here we come upon another equally diffi- 

 cult problem. It relates to the proportion of 

 embryonic or individual fluctuation, to partial 

 variation as involved in the process of selec- 

 tion. Probably all qualities which may be sub- 

 jected to selection vary according to both prin- 

 ciples, the embryonic decision giving only a 

 more definite average, around which the parts 

 of the individual are still allowed to oscillate. 

 It is so with the corn, and whenever two 

 or more ears are ripening or even only flower- 

 ing on the same plant, differences of a partial 

 nature may be seen in the number of their rows. 

 These fluctuations are only small however, or- 

 dinarily not exceeding two and rarely four 



