Gottlieb Haberlandt

Wilson reports that Haberlandt studied the position of the nucleus in plant cells, with special regard to growth of the cellulose membrane. Local growth of the wall was found to be preceded by movement of the nucleus to the growing point¹. Haberlandt's own summary was that the nucleus lies near the points where growth is most active and lasts longest². Wilson drew from this that the nucleus has a definite part in growth of the cell and of its wall. Hairs with the nucleus at the base were read as confirming the rule, because those hairs grow from the base².

Wilson cites a further observation by Haberlandt. In regenerating fragments of Vaucheria, the growing region where a new membrane forms contains no chlorophyll but many nuclei³. Morgan, writing on regeneration, places Haberlandt and Gerassimoff beside Hofer among those who found that pieces without a nucleus fail to regenerate. He sets this next to Verworn's results on protozoa⁴. Morgan adds that Palla found some non-nucleated pieces from growing regions could still form a new cell wall⁴.

Bose treats Haberlandt, with Pfeffer, as a main supporter of a hydro-mechanical account of how Mimosa carries a stimulus. In Haberlandt's experiment a tissue was killed by scalding, and the stimulus still crossed it⁵. Haberlandt compared the transmission to pressure in a water-filled rubber tube⁶. He held that the channel is certain tubular cells in the phloem, not the xylem vessels that Pfeffer favoured⁷. Bose objected that superficial scalding hardly guarantees that interior tissue is dead⁸.