Oken was therefore right when, more divining than knowing, he made the assertion—“Every organic thing has arisen out of slime, and is nothing but slime in different forms. This primitive slime originated in the sea, from inorganic matter in the course of planetary-evolution.” Another equally grand idea of the same philosopher is closely connected with his theory of primitive slime, which coincides with the extremely important _Protoplasm theory_. For Oken, as early as 1809, asserted that the primitive slime produced in the sea by spontaneous generation, at once assumed the form of microscopically small bladders, which he called “_Mile_,” or “_Infusoria_.” “Organic nature has for its basis an infinity of such vesicles.” These little bladders arise from original semi-fluid globules of the primitive slime, by the fact of their periphery becoming condensed. The simplest organism, as well as every animal and every plant of higher kind, is nothing else than “an accumulation (synthesis) of such infusorial bladders, which by various combinations assume various forms, and thus develop into higher organisms.” Here again we need only translate the expression _little bladder_, or _infusorium_, by the word _cell_, and we arrive at the Cell theory, one of the grandest biological theories of our century. Schleiden and Schwann, about thirty years ago, were the first to furnish experiential proof that all organisms are either simple cells, or accumulations (syntheses) of such cells, and the more recent protoplasm theory has shown that protoplasm (the original slime) is the most essential (and sometimes the only) constituent part of the genuine cell. The properties which Oken ascribes to his Infusoria are exactly the properties of cells, the properties of elementary beings, by whose accumulation, combination, and varying development, the higher organisms are formed.