The cell in development and inheritance / by Edmund B. Wilson.

  • Edmund Beecher Wilson
Date:
1902, ©1900
Catalogue details

Licence: Public Domain Mark

Credit: The cell in development and inheritance / by Edmund B. Wilson. Source: Wellcome Collection.

Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.

    127/522 (page 99)
    Normal multipolar mitoses, though rare, sometimes occur, as in the division of the pollen-mother-cells and the endosperm-cells of flower- ing plants (Strasburger); but such mitotic figures arise through the union of two or more bipolar amphiasters in a syncytium and are due to a rapid succession of the nuclear divisions unaccompanied by fission of the cell-substance. These are not to be confounded with pathological mitoses arising by premature or abnormal division of the centrosome. If one centrosome divide, while the other does not, triasters are produced, from which may arise three cells or a tri- nucleated cell. If both centrosomes divide, tetrasters or polyasters are formed. Here again the same result has been artificially attained by chemical stimulus {cf. Schottlander, 'Z^). Multipolar mitoses are A B Fig. 47. — Pathological mitoses in epidermal cells of salamander caused by p>oisons, [Galeotti.] A. Asymmetrical mitosis after treatment with 0.05 % antipyrin solution. B. Tripolar mitosis after treatment with 0.5 % potassic iodide solution. also common in regenerating tissues after irritative stimulus (Strobe); but it is uncertain whether such mitoses lead to the formation of normal tissue.^ The frequency of abnormal mitoses in pathological growths is a most suggestive fact, but it is still wholly undetermined whether the abnormal mode of cell-division is the cause of the disease or the reverse. The latter seems the more probable alternative, since nor- mal mitosis is certainly the rule in abnormal growths ; and Galeotti's experiments suggest that the pathological mitoses in such growths may be caused by the presence of deleterious chemical products in the diseased tissue, and perhaps point the way to their medical treatment. ^ The remarkable polyasters formed in polyspermic fertilization of the egg are de- scribed at page 198.