30 LUTHER BURBANK 



from it a variety in which the brucine is reduced 

 to a minimum, or, if possible, wholly removed. 



The seeds received were of various colors. 

 My first move was to have the seeds sorted, 

 placing white ones, black ones, and green and 

 brown by themselves. They were then planted 

 in separate lots; a fifth lot being reserved for a 

 mixture of the seeds of uncertian shades. 



Thus it was possible at the outset to determine 

 whether the production of plants having a 

 large brucine content was associated with any 

 particular color of seeds. Should such be found 

 to be the case, the experiment would obviously 

 be shortened, as only the plant bearing the mini- 

 mum amount of brucine would be used for fur- 

 ther testing. Experiments showed that the 

 plants from the white seed apparently contained 

 an appreciably less quantity of brucine than the 

 black ones. 



As an additional element in the selection, I 

 chose, as is my custom, the seed plants that 

 started very early in the spring. From among 

 these the next selection was made of the plants 

 that had broad foliage and continued to make a 

 very strong growth. Thu& several objects were 

 attained almost from the outset. A second se- 

 lection along the same lines showed that some 

 plants have a much smaller brucine content than 



