From an early age Hugo showed much interest in botany, winning several prizes for his herbariums while attending gymnasium in Haarlem and The Hague.
After a short period of teaching, de Vries left in September 1870 to take classes in chemistry and physics at the Heidelberg University and work in the laboratory of Wilhelm Hofmeister.
To support his theory of pangenes, which was not widely noticed at the time, de Vries conducted a series of experiments hybridising varieties of multiple plant species in the 1890s.
Unaware of Mendel's work, de Vries used the laws of dominance and recessiveness, segregation, and independent assortment to explain the 3:1 ratio of phenotypes in the second generation.
In the late 1890s, de Vries became aware of Mendel's obscure paper of thirty years earlier and he altered some of his terminology to match.
In 1886, he had discovered new forms among a group of Oenothera lamarckiana, a species of evening primrose, growing wild in an abandoned potato field near Hilversum, having escaped a nearby garden.
In his two-volume publication The Mutation Theory (1900–1903) he postulated that evolution, especially the origin of species, might occur more frequently with such large-scale changes than via Darwinian gradualism, basically suggesting a form of saltationism.
De Vries's theory was one of the chief contenders for the explanation of how evolution worked, leading, for example, Thomas Hunt Morgan to study mutations in the fruit fly, until the modern evolutionary synthesis became the dominant model in the 1930s.
During the early decades of the twentieth century, de Vries' theory was enormously influential and continued to fascinate non-biologists long after the scientific community had abandoned much of it[7] (while retaining the idea of mutations as a crucial source of natural variation).
However, the popular understanding of "mutation" as a sudden leap to a new species has remained a staple theme of science fiction, e.g. the X-Men movies (and the comic books that preceded them).