LUTHER BURBANK 



tagonistic characters that show the phenomena of 

 dominance and recessiveness. 



It follows that if a character which you are 

 striving to fix in any given experiment is a re- 

 cessive character, it is fixed from the moment 

 when it reappears and you may give yourself no 

 further concern in the matter. But if it be a 

 dominant character, then you must be on the look- 

 out, since of every three specimens that show the 

 character, two will have factors for the antag- 

 onistic character in their germ-plasm, and do 

 not constitute fixed strains. Only by watching 

 through another generation can it be determined 

 which individuals are "pure dominants," and 

 such alone will breed true. 



Until the Mendelian formula was known breed- 

 ers were often put to their wits' end to segregate 

 a strain that would breed true ; whereas now, with 

 the formula in mind, this may usually be accom- 

 plished in two generations. 



'S 



LOOKING FORWARD 



In the preceding pages a few of the general 

 principles of plant development have been out- 

 lined, by way of a preliminary sketch of Mr. Bur- 

 bank's methods. In the chapters that follow these 

 methods will be illustrated at greater length and 

 in much fuller detail. It seemed well, however, to 

 prepare the reader with this preliminary outline 

 for the detailed studies that are to follow. 



In the immediately succeeding chapters, we 

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