A text-book of pathology for students of medicine / by J. George Adami and John McCrae.
- John George Adami
- Date:
- 1914
Licence: In copyright
Credit: A text-book of pathology for students of medicine / by J. George Adami and John McCrae. Source: Wellcome Collection.
14/904 page 18
![IS little attention ordinarily from the histologist and l)iologist; these have to be brought forward in their pro])er rehitionshij). ddiis first ehapter, therefore, is devoted to the proi)erties of the cell, and attemj)ts to show how it is eonstituted, how cell interacts on cell, how a com- munity reacts upon community—in short, how the cell is at once a unit and a necessary part of a great aggregation of units. If the cell be regarded as an individual, it will be seen that, like a human })eing, it IS born, grows, eats, casts out excretion, rests, is active, becomes useful, learns the work it is destined to do, fills its place in the communitv, falls sick, recovers, meets with accidents, is set upon by enemies in the shape of infections, enemies which it conquers or by which it is over- come, grows old, dies, and has its place taken by another like it. So far there is a parallel between a man and a cell; and it may be carried farther. The statement is made upon good authority that no man liveth unto himself, because a man’s deeds react not only upon himself but upon others, in however indirect a way; so the cell, as part of a community (the organ), cannot withdraw itself from communication with its fellows, but must bear its share of the labor of the organ, and its ill or well-being will react upon the cells that are near it or that depend in any way upon it. The Constituents of the Cell.—The animal cell consists of two main parts, the nucleus and the cell body, and even if it cannot be agreed that there is, in all animal and vegetable cells, a nucleus in definite form, we can at least say that there is nuclear and cytoplasmic material. In the cells of man the nucleus has a definite form, generally round or oval; a nuclear membrane can frequently be made out, and inside this the substance shows an alveolar or netted arrangement. The nuclear matter can be demonstrated to consist of (1) the linin or achromatic (non-staining) network in which is deposited (2) the chromatin—the material which is stainable by nuclear dyes. In the spaces is (3) the nuclear fluid. Not always distinguishable are the following: (a) The nucleolus, (Fig. 1, b), an accumulation of nuclear material which stains differently to the nucleus at large, and is prcr sumed to be of a different, or at least temporarily different, composition; {b) vacuoles, which are rare, but may be seen in the nuclei of fat cells (see Fig. 2) and (c) crystals. The last two are products of the activity of nuclear metabolism. The type cell has but a single nucleus; but at times two or many nuclei may be present, a condition which may be due, on the one hand, to division of the nucleus with failure of the cytoplasrh to divide, or, on the other, to fusion of separate cells. Both processes evidently occur, as will be discussed when dealing with giant cells. Although we say that the nuclear material is confined to the nucleus proper, it must be realized that there is a constant interchange of material between nucleus and cytoplasm. INIany of the granules or formed bodies seen in the cytoplasm, such as the Nissl or tigroid bodies](https://iiif.wellcomecollection.org/image/b28055172_0014.jp2/full/800%2C/0/default.jpg)
