What did Hugo de Vries discover in the evening primrose?

In 1889, De Vries published his book Intracellular Pangenesis , in which, based on a modified version of Charles Darwin's theory of Pangenesis of 1868, he postulated that different characters have different hereditary carriers. He specifically postulated that inheritance of specific traits in organisms comes in particles. He called these units pangenes, a term 20 years later to be shortened to genes by Wilhelm Johannsen.





To support his theory of pangenes, which was not widely noticed at the time, De Vries conducted a series of experiments hybridising varieties of plants in the 1890s and he discovered new forms among a display of the evening primrose (Oenothera lamarckiana) growing wild in a waste meadow. His experiments led to the same conclusions as Mendel and confirmed his hypothesis: that inheritance of specific traits in organisms comes in particles