Lamarck's exposition of the evolution theory and particularly of its causes, with the great stress laid upon the principle of the inheritance of acquired characters, and hence the all-import ant influence and effect of varying environment in the modification of species, has come to be known in evolution literature as "Lamarckism" in contrast with "Darwinism," or Charles Dar win's contribution with its special emphasis on natural selection as the explanation of the "origin of species." "Darwinism" is too often popularly used synonomously with evolution, but it should not be so used. "Darwinism" is a convenient inclusive name for Darwin's ex planations of evolution; his theories of natural and sexual selection.
Contemporary with Lamarck were Goethe (1749-1832) who contributed somewhat to the evolution theory by his studies and generaliza tions on the metamorphosis of plants and the vertebrate theory of the skull, and Saint Hilaire (1772-1844) who maintained insistently the truth of the evolution theory, then being ob scured by the antagonism of Cuvier, but who denied the inherited influences of habit, holding that the direct modifying action of environment on organisms was the sole cause of species forming.
But it was Charles Darwin (1809-82) who was first able to restore and extend enor mously the prestige of the evolution conception. This was due first to his tremendous marshal ing of facts to support it, and, second, to his contribution of a new, or practically new, causo-mechanical explanation of species change, or, as usually expressed, °origin of species.° It is Darwin's great merit to have wholly re-estab lished the theory of descent and to have offered the first explanation of
that made a really winning appeal to biologists generally. It was also his fortune to bring the evolution concep tion home to the people. Up to the publication of his
great zoologist and bold speculative monist phi losopher of Jena, was the principal continental contemporary champion of Darwinism.
A curious incident in the history of the Dar winian evolution exposition and explanation is that of the extraordinary coincidence of the formulation of the natural selection theory by Alfred Russel Wallace at the very same time of its utterance by Darwin. As a matter of fact both men published papers formulating this theory in 1858 in a single number of the Jour nal of the Linnman Society The name of Wells (1813), Matthews (1831) and Nandin (1852), are often mentioned as those of men who anticipated in some measure, at the various dates indicated, Darwin's utterance of the selec tion theory, by more or less clear statements of its essence, but none of them carried conviction to the world.
The post-Darwinian history of evolution has chiefly to do with the further development of the Darwinian theories, together with the rise of the so-called '
Bibliography.— Clodd, Edward,