476 



EVOLUTION, GENETICS, AND EUGENICS 



"Lamarck's evening-primrose" (Fig. 91), says De Vries, "is a 

 stately plant, with a stout stem, attaining otten a height of 1.6 meters 

 and more. When not crowded the main stem is surrounded by a large 



Fig. 91. — Oenothera lamarckiana, the original type used by DeVries in his 

 experiments. This is the stock from Hilversum, from which arose in successive 

 generations a series of mutants. {From De Vries.) 



