Note 6 — THE INDIVIDUAL ORGANISM WITH REGARD TO FORM AND METABOLISM

The older theories, attributing to fertilisation (or to “conjugation,” i.e. its equivalent in Protozoa), some sort of “renovation” or “rejuvenescence” of the race, have been almost completely given up. (See Calkins, Arch. für Entwickelungsmechanik, xv. 1902). R. Hertwig recently has advocated the view, that abnormal relations between the amounts of nuclear and of protoplasmatic material are rectified in some way by those processes. Teleologically, sexual reproduction has been considered as a means of variability (Weismann), but also as a means of preserving the type!