The cell : outlines of general anatomy and physiology / by Oscar Hertwig ; translated by M. Campbell ; and edited by Henry Johnstone Campbell.

  • Campbell M.
Date:
1895
Catalogue details

Licence: Public Domain Mark

Credit: The cell : outlines of general anatomy and physiology / by Oscar Hertwig ; translated by M. Campbell ; and edited by Henry Johnstone Campbell. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    that, at first sight, they seem to have nothing in common, and that hence it is impossible to compare them. For instance, if a cell at the growing-point of a plant be taken and compared with one filled with starch granules from the tuber of a potato, or if the contents of an embryo cell from a germinal disc be com- pared with those of a fat cell, or of one from the egg of an Amphibian filled with yolk granules, the inexperienced observer sees nothing bat contrasts. Nevertheless, all these exceedingly different cells are seen on closer examination to be similar in one respect, i.e. in the possession of a very important, peculiar mix- ture of substances, which is sometimes present in large quantities, and sometimes only in traces, but which is never wholly absent in any elementary organism. In this mixture of substances the wonderful vital phenomena, which are dealt with later, may very frequently be observed (contractility, irritability, etc.); and, more- over, since in young cells, in lower organisms, and in the cells of growing-points and germinal areas, it is in the cell-substance alone (the nucleus of course being excepted) that these properties have been observed, this substance has been recognised as the chief supporter of the vital functions. It is the protoplasm or “forming matter” of the English histologist, Beale (I. 3). a. Justification of the Use of the Term Protoplasm. In order to know what protoplasm is, it is advisable to examine it in those cells in which it is present in large quantities, and in which it is as free as possible from admixture with other bodies ; and amongst such the most suitable are those organisms from the study of which the founders of the protoplasmic theory formed their conception of the nature of this substance. Such organisms are, young plant-cells, Amoebae, and the lymph corpuscles of vertebrates. After the student has learnt to recognise the cha- racteristic properties of protoplasm in such bodies, he will be able to discover it in others, in which it is only present in small quantities and is more or less concealed by other substances. It has been proposed (II. 10) to give up altogether the use of the term protoplasm, since it has been associated with such mistaken views; for the word has now come to be used in so indefinite and vague a manner, that it may be questioned whether it is not at present more misleading than useful. However, this proposition cannot be considered to be advisable or even justifiable in the present condition of affairs, for, although it must be admitted that the word is frequently used incorrectly;
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