First report on the cytological investigation of cancer : 1906 / by J.E.S. Moore and C.E. Walker.

  • Moore, J. E. S.
Date:
[1906]
Catalogue details

Licence: In copyright

Credit: First report on the cytological investigation of cancer : 1906 / by J.E.S. Moore and C.E. Walker. Source: Wellcome Collection.

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    Part I. MAIOTIC PHENOMENA, CELL DIVISIONS, AND GROWTH. 1. All enquiries relating to the life and growth of living things resolve themselves ultimately into cell problems, all vital processes being manifestations of the activity, growth and multiplication of living cells. In itself a cell may be described as the simplest protoplasmic arrangement that can lead an independent existence. A cell is constituted morphologically of a nucleus and its associated cytoplasm. These protoplasmic units may be separate from one another as in the protozoa, or they may remain in connection as in our own bodies. In the latter case they may be divided from one another by partitions, or they may be merely differentiated as independent centres of influence in a continuous protoplasmic mass. Neither the cytoplasm nor the nuclei of cells are simple substances, but even under the microscope are found to be visibly complex jellies, built up in the manner of foam, or the structure of a coarse colloid as it is understood by the modern chemist. Simple cells when immersed in suitable media, grow by converting the constituents of surrounding fluids into their own substance. Although the exact modus operandi of the process of growth is not understood, the act of growing is generally accompanied by a most remarkable phenomenon. While it is proceeding, each cellular unit divides like a drop into two drops, and these distinct processes of growth and division may go on indefinitely. When first observed the process of division was supposed to be analogous to the division of a simple drop into two, but the recent advances in our knowledge of the process have shown it to be of astonishing order and complexity. When a cell is at rest it appears to be a coarsely colloid jelly, within which there is a spheroidal area of distinct substance of the same nature—the nucleus. When the cell is about to divide the nucleus breaks up into a number of discreet parts composed generally of short band like bodies consisting of a dense material in which there is a variable amount of a substance—chromatin—that stains intensely with aniline dyes. These bodies— the chromosomes—lie within the nuclear area in a less stainable fluid. The most remarkable fact about them is that their number is constant for any particular animal or plant. In the cells composing the body of a man there are 32, in those of a donkey 36, and so on. 2. The fact that the number of the chromosomes is constant in the bodies of animals and plants is most remarkable, and its interest has been still further increased through the investigations of Flemming, Strasburger, van Beneden and many others, who showed that in every normal cell division, each of the chromosomes splits from end to end, and the halves so produced pass to the daughter cells as the whole mass divides. In this way when a cell divides we have in each daughter element the same number of half chromosomes as there were whole chromosomes in the parent cell. These half-chromosomes, collecting together in each of the daughter cells, become surrounded by a membrane, and swell up to form the same kind of spheroidal body as the nucleus of the parent cell, before the process of division began. 3. The constant number of the chromosomes appearing in each division has long suggested to cytologists that, though these bodies cannot be distinguished in most cases during the resting condition of the cell, they nevertheless must be present, or their number