Jena, Gustav Fischer, 1889. 8vo (22.2 x 14.2 cm). vi, 212 pp. Slightly later yellow cloth with the original front wrapper mounted on the front board.

First edition of Hugo De Vries's theory of heredity, and in particular: "[T]he introduction of the idea of determinants of organic characters, understood as separable material elements which can be distributed randomly in descendants. Starting from the question of heredity, such as it was defined by Darwin in 1868, and after its critical developments by August Weismann, Hugo De Vries was able to suggest such an idea in his Intracellular Pangenesis. He then laid out a programme of research which helps us to understand the 'rediscovery' published in 1900." (C. Leney). With a quote from Darwin printed on the front wrapper: "An organic being is a microcosm, a little universe, formed of a host of self-propagating organisms, inconceivably minute and numerous as the stars in heaven". Private owner's small blind-stamp in top margin of the title page, title page and subsequent leaf with two tiny, marginal tears, otherwise a very good, clean copy. Rare. Stafleu and Cowan, 16.374.