But the light must have its attendant shadow, and all his carefulness in observation and cautiousness in judgment did not protect him from one prejudice and its evil consequences. After Moldenhawer had isolated the elementary organs by maceration, he had to answer the question how we are to conceive of their firm coherence in the living plant. He came to the conclusion, as did von Mohl, Schacht, and others after him, that there must be some special connecting medium; but he did not hit upon their idea of a matrix, in which the cells are imbedded, or of a cement which holds them together, but on a much stranger theory, which reminds us at once of Grew’s thread-tissue, and like that rests partly on incorrect observations. These were too hastily accepted as the basis of a theory which in its turn interfered with after observations. He thought that the cells and vessels were surrounded and held together by an extremely delicate network of fine fibres; in some cases he really believed that he saw these fibres, and interpreted in this way the thickened bands in the well-known cells of Sphagnum, and still more strangely he appears to have taken the thickened longitudinal and transverse edges of cells and vessels for such threads. The unfavourable impression produced by this theory is necessarily heightened by the fact that he gave the name of cell-tissue, a term long used in a different sense, to his fancy-structure of reticulated threads which were to hold the cells and vessels together, while he called the parenchyma itself cellular substance, an expression which fortunately no one copied, and which certainly contributed at a later time to discredit the great services which Moldenhawer rendered to phytotomy. His ‘Beiträge zur Anatomie der Pflanzen’ are divided into two portions; the first treats of the parts surrounding the spiral vessels; the second of the spiral vessels themselves.