(4) Hugo de Vries (1848—1935), a Dutch botanist, one of the independent rediscoveries of Mendelism, put forward his views regarding the formation of new species in 1901. He also met some of the objections found in Darwin’s theory. According to him, new species are not formed by continuous variations but by sudden appearance of variations, which he named as mutations. Hugo de Vries stated that mutations are heritable and persist in successive generations. The theory states that evolution is a jerky process where new varieties and species are formed by mutations (discontinuous variations)that function as raw material of evolution. The salient features of mutation theory are: Mutations or discontinuous variations are the raw material of evolution. Mutations appear all of a sudden. They become operational immediately. Unlike Darwin’s continuous variations or fluctuations,mutations do not revolve around the mean or normal character of the species. The same type of mutations can appear in a number of individuals of a species. All mutations are inheritable. Mutations appear in all conceivable directions. Useful mutations are selected by nature. Lethal mutations are eliminated. However, useless and less harmful ones can persist in the progeny. Accumulation of variations produces new species. Sometimes a new species is produced from a single mutation. Evolution is a jerky and discontinuous process.