Species and Varieties, Their Origin by Mutation

Hugo Marie de Vries  (February 16, 1848 – May 21, 1935) was a Dutch botanist and one of the first geneticists. He is known chiefly for suggesting the concept of genes, rediscovering the laws of heredity in the 1890s while unaware of Gregor Mendel's work, for introducing the term "mutation", and for developing a mutation theory of evolution. 

In the book «Species and Varieties, Their Origin by Mutation» is a technical scientific work that became a necessity intelligible to a wider circle of readers. The author was doubtless greatly aided in the successful solution of the problem by the difference of origin of the two works. " Die Mutationstheorie " is primarily a detailed exposition of the results of research, and was addressed to scientists who would appreciate nay, demand all the evidence on which are based the far-reaching generalizations involved in the theory of mutation. "Species and Varieties” on the other hand, having grown out of a series of lectures delivered by the, author, before the students of a university, assumes in consequence a much less rigid scientific aspect, becoming by necessity intelligible to a wider circle of readers!