52 The Third and Fourth Generation 



It seemed to the farmer a pitifully small crop, 

 but to the expert a very hopeful one — two 

 plants, at least, that were disease-resistant. 

 Seed reared from these produced similar healthy 

 cabbages on farms that had been unable to 

 get a crop with the ordinary cabbage seed for 

 years. And now with this new disease-resist- 

 ant variety the region is returning with assur- 

 ance to its very profitable industry. 



Many other instances might be cited of the 

 sudden appearance of new breeds of animals 

 or new varieties of plants. Such have been 

 long known and have been called "sports." 

 Hugo de Vries, a Holland botanist, obtained 

 seed of an evening primrose, at one time prob- 

 ably a native of Southwestern United States. 

 He planted acres of this "weed" in his experi- 

 mental garden near Amsterdam. He dis- 

 covered that among thousands of plants which 

 bred true to the original primrose, Oenothera 

 lamarckiana, there also appeared plants so 

 unlike as to be evidently new species, and these 

 bred true. There was one with flowers double 

 the size of those of the parent species. The 



