The student buried himself in the phenomenon of cell colonies; he read about half-organisms, algae, whose single cells, enveloped in a mantle of gelatine, often lay apart from one another, yet were multiple-cell formations, which, if they had been asked, would not have known whether to be rated as a settlement of single-celled individuals, or as an individual single unit, and, in bearing witness, would have vacillated quaintly between the I and the we. Nature here presented a middle stage, between the highly social union of countless elementary individuals to form the tissues and organs of a superior I, and the free individual existence of these simpler forms; the multiple-celled organism was only a stage in the cyclic process, which was the course of life itself, a periodic revolution from procreation to procreation. The act of fructification, the sexual merging of two cell-bodies, stood at the beginning of the upbuilding of every multiple-celled individual, as it did at the beginning of every row of generations of single elementary forms, and led back to itself.