Protoplasm : its definition, chemistry and stucture / by Gustav Mann.

  • Mann, Gustav, 1864-1921.
Date:
1906
Catalogue details

Licence: In copyright

Credit: Protoplasm : its definition, chemistry and stucture / by Gustav Mann. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    AND j STRUCTURE OF PROTOPLASM. (By Gustav Mann, M.D. Edinburgh, B.Sc. Oxon, Physiological ^ Laboratory, Oxford.) Hugo v. Mohl' described in 1844 the ‘primordial utricle’ as a membrane composed of a nitrogenous compound lying on the inner side of vegetable cell-membranes, and also stated that it occurred in the Confervae without a nucleus, and that it persisted in chlorophyll-containing cells after the nucleus had been absorbed. These observations no doubt led him to the theory expressed in 1846* that ‘the semi-fluid, nitrogenous substance contained in the cell ... is the pre- cursor of the solid constituents found subsequently in a developing cell, and that it supplies the material for the formation of the nucleus and the primordial utricle.’ This physiological consideration led him to introduce the word protoplasma. .Protoplasm is therefore, according to v. Mohl’s definition, the mother-substance of the cell membranes and of the nucleus. That this conception is diametrically opposite to the one held by me will be shown later, and will, I hope, ' H. V. Mohl, Botanische Zeituug, 1844, pp. 273, 289, 305, 326, 337. * Ibid., 1846, pp. 73, 89. B 2