In the February number of _Harper's Monthly_ for 1903, Professor Thomas Hunt Morgan, Professor of Biology at Bryn Mawr, and one of the best known of our American biologists, whose recent work on "Regeneration" has attracted favorable notice all over the world, calls attention to the revolutionary character of Mendel's discovery. He considers that recent demonstrations of the mathematical truth of Mendel's Law absolutely confirm Mendel's original observations, and the movement thus initiated, in Professor Morgan's eyes, gives the final _coup de grace_ to the theory of natural selection. "If," he says, "we reject Darwin's theory of natural selection as an explanation of evolution, we have at least a new and promising outlook in another direction and are in a position to answer the oft-heard but unscientific query of those who must cling to some dogma: if you reject Darwin, what better have you to offer?" {198} Professor Edmund B. Wilson, the Director of the Zoological Laboratory of Columbia University, called attention in _Science_ (19 December, 1902) to the fact that studies in cytology, that is to say, observations on the formation, development, and maturation of cells, confirm Mendel's principles of inheritance and thus furnish another proof of the truth of these principles. Two students working in Professor Wilson's laboratory have obtained definite evidence in favor of the cytological explanation of Mendel's principles, and have thus made an important step in the solution of one of the important fundamental mysteries of cell development in the very early life of organisms. In a paper read before the American Academy of Arts and Sciences last year, Professor W. E. Castle, of Harvard University, said with regard to Mendel's Law of Heredity:-- What will doubtless rank as one of the greatest discoveries in the study of biology, and in the study of heredity, perhaps the greatest, was made by Gregor Mendel, an Austrian monk, in the garden of his cloister, some forty years ago. The discovery was announced in the proceedings of a fairly well-known scientific society, but seems to have attracted little attention, and to have been soon forgotten. The Darwinian theory then occupied the centre of the scientific stage, and Mendel's brilliant discovery was all but unnoticed for a third of a century. Meanwhile, the discussion aroused by Weissman's germ plasm theory, in particular the idea of the non-inheritance of acquired characters, put the scientific public into a more receptive frame of mind. Mendel's law was rediscovered {199} independently by three different botanists, engaged in the study of plant hybrids--de Vries, Correns, and Tschermak, in the year 1900. It remained, however, for a zoologist, Bateson, two years later, to point out the full importance and the wide applicability of the law. Since then the Mendelian discoveries have attracted the attention of biologists generally. [Footnote 15]