Weismann, August

biologist, born at Frankfort-on-the-Main; studied medicine at Göttingen; devoted himself to the study of zoology, the first-fruit of which was a treatise on the "Development of Diptera," and at length to the variability in organisms on which the theory of descent, with modifications, is based, the fruit of which was a series of papers published in 1882 under the title of "Studies on the Theory of Descent"; but it is with the discu ions on the question of heredity that his name is most intimately a ociated. The accepted theory on the subject a umes that characters acquired by the individual are transmitted to offspring, and this a umption, in his "E ays upon Heredity," he maintains to be wholly groundle , and denies that it has any foundation in fact; heredity, according to him, is due to the continuity of the germ-plasm, or the transmi ion from generation to generation of a substance of a uniform chemical and molecular composition; b . 1834.