LUTHER BURBANK 



else record of the hybridizations after they become 

 very complex. 



For a good many years, to be sure, I kept accu- 

 rate check on the various crosses. 



The names of the parents used in an original 

 hybridizing experiment were always recorded. 



Later, as the cross became more complex, large 

 numbers of species being utilized, I attempted 

 short cuts by using numbers and letters on my 

 labels, the key to these being recorded in my plan 

 books. 



This worked very well for a few years more. 

 But there came a time when an experiment with 

 a single strain of roses had been carried through 

 so many generations that the traits of ten species 

 or more would be combined in an individual. 



At this stage I abandoned the numbers and 

 letters, and contented myself with a general knowl- 

 edge of the principal ancestors in the pedigree of 

 any new variety, distinguishing the new variety 

 itself by a temporary name for purposes of further 

 record. 



Thus I have, for example, grown upward of 

 two hundred thousand seedlings from the Crim- 

 son Rambler pollenated with all the ordinary roses 

 that are under cultivation in California. The pol- 

 len of only a few of them proved effective. But 

 here and there a rose like the Empress of India or 



[58] 



