Born Feb. 16, 1848, in Haarlem; died May 21, 1935, in Lunteren. Dutch botanist.
Educated at Leiden, Heidelberg, and Würzburg, de Vries was a professor at the University of Amsterdam and director of the botanical garden from 1878 to 1918. Later he continued his work at his estate in Lunteren. De Vries developed a method of determining osmotic pressure in plants and showed that it depends on the number of molecules of matter in a given volume (1877). He was one of the scientists who independently rediscovered Mendel’s laws and a founder of the theory of mutation and evolution (1900). Observing the variability of Oenothera (an evening primrose), de Vries concluded that a species may suddenly break up into a large number of different species. De Vries called this phenomenon mutation and concluded that biological species periodically enter a mutating phase. This view was the basis of de Vries’ “mutation theory,” which is sometimes, wrongly, contrasted with Darwin’s theory. Like Darwin, de Vries believed that adaptation resulted from natural selection. He regarded the species as a narrower taxonomic category than did Darwin.
V. L. RYZHKOV