Experimental Pedigree-Cultures 563 



from the beginning, nor does it need any natural 

 or artificial aid if it is present. Most of my 

 new species Have proved constant from the first. 

 Whenever possible, the original mutants have 

 been isolated during the flowering period and 

 artificially self-fertilized. Such plants have al- 

 ways given a uniform progeny, all children ex- 

 hibiting the type of the parent. No atavism 

 was observed and therefore no selection was 

 needed or even practicable. 



Briefly considering the different forms, we 

 may state that the full experimental proof has 

 been given for the origin of gig as and rubriner- 

 vis, for albida and oblonga, and even for nor 

 nella, which is to be considered as of a varietal 

 nature ; with lata the decisive experiment is ex- 

 cluded by its unisexuality. Laevifolia and 

 br,evistylis were found originally in the field, 

 and never appeared in my cultures. No obser- 

 vations were made as to their origin, and seeds 

 have only been sown from later generations. 

 But these have yielded uniform crops, thereby 

 showing that there is no ground for the assump- 

 tion that these two older varieties might behave 

 otherwise than the more recent derivatives. 



Scintillans and elliptica constitute exceptions 

 to the rule given. They repeat their character, 

 from pure seed, only in part of the offspring. I 

 have tried to deliver the scintillans from this 



