See Th. Boveri, Ergebnisse ueb. d. Konstitution d. chromatischen Substanz des Zellkerns (1903), for the most recent defence of this view. He lays, however (p. 2), far more stress on the individuality of the segments themselves than on the actual chromatin material they contain.
The fact that it is by mitotic division that the undifferentiated germ-cells produce the "differentiated" tissue-cells of the body of the highest animals, is again irreconcilable with such theories, whose chief advocates have been A. Weismann and his disciples.
Temporary plastogamy is a process found in some Foraminifera, where two organisms unite by their cytoplasms so that there can be complete blending of these, while the nuclei remain distinct: they ultimately separate again. In the conjugation of the Infusoria, the union of the cytoplasms is a temporary plastogamy (see p. [148] f.).
See Figs. 9, 29, 31, 34, etc., pp. [54], [89], [95], [101].
One obvious effect of brood-formation is to augment rapidly the ratio of superficial area to bulk: after only three divisions (p. [23], note) the ratio is doubled; if the divisions be nine in succession so as to produce a brood of 512, the ratio is increased eightfold, on the supposition that the figure is preserved. However, the brood-mother-cell is usually spherical, while zoospores are mostly elongated, thus giving an additional increase to the surface, which we may correlate with that increased activity; so that they disseminate the species, spreading far and wide, and justifying the name of "spore" in its primitive sense (from the Greek σπείρω—I scatter [seed]).