Protoplasm : its definition, chemistry and stucture / by Gustav Mann.
- Gustav Mann
- Date:
- 1906
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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![sence of inorganic and organic electrolytes]. Two important papers by Pauli ‘ and Hofmeister' have also appeared dealing with protoplasm from the physico-chemical and the chemical points of view, and I have to content myself by drawing attention to them, with the exception of quoting one passage from Hofmeister: ‘ Even now, we may say, that the con- templation of the cell as a machine working with chemical and physico-chemical means leads nowhere to problems which could compel us to assume other than known forces, and, as far as we can see, there is no reason for that resignation, which either expresses itself in an ‘ ignorabimus ’ or in vital- istic deductions.’ Definition of Protoplasm. At the beginning of this paper Hugo von Mohl’s reason for speaking of protoplasm was given. He conceived it to be the mother substance of the nucleus and the cell-envelopes. This conception is, however, no longer tenable. In my paper ‘ What is Life?’ I pointed out in 1898'' that ‘organic individuals possess the power of creating around themselves a new en- vironment, the cytoplasm, which has the following functions : (1) To elaborate possible inorganic or organic food substances and thereby to make them directly assimilable by the nucleus (chloroplasts and zymogen-granules). (2) To protect the nucleus from deleterious influences outside the organic indivi- dual (as proved by the removal of the whole or greater part of the cytoplasm, invariably leading to the death of the nucleus). (3) To either attract food to the cell or to move the cell towards the food by means of the centrosomes which are to be regarded as special locomotor organs {viz : centrosomes in white blood corpuscles (M. Heidenhain), * Pauli: Dcr KoUoidale Zustand und die Vorgdnge in der Icbendigen Snb~ slans; Brauuschiveig, Vieiveg, 1902. “ Hofmeister: Die chemische Organisation der Zelle; Braunschweig, Vieweg, 1901. * Mann, Trans. O.xford University Junior Scient. Club, 1899.](https://iiif.wellcomecollection.org/image/b22471303_0059.jp2/full/800%2C/0/default.jpg)
