General physiology; an outline of the science of life (1899) (14780495964)

Identifier: generalphysiolo00verw (find matches)
Title: General physiology; an outline of the science of life
Year: 1899 (1890s)
Authors: Verworn, Max, 1863-1921 Lee, Frederic S. (Frederic Schiller), 1859-1939, ed. and tr
Subjects: Physiology
Publisher: London, Macmillan and co., limited New York, The Macmillan company
Contributing Library: Columbia University Libraries
Digitizing Sponsor: Open Knowledge Commons



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xa pallida. A rhizopod contain-ing very finely-divided nuclear substance(After Gruber.) 68 GENERAL PHYSIOLOGY characterises all other cells. There are also among animals varietiesof cells that show quite the same quantitative relation of the twosubstances to each other; an example of such is afforded by thesperm-cells, or spermatozoa, which consist of a large quantity ofnuclear substance and a very small quantity of protoplasm. Thus, from the present state of our knowledge, it appears thatamong the organisms now living upon the earth there are no cellsin which a separation of two different substances is not present,but that every cell possesses a nucleus in addition to the proto-plasm. It is, of course, another question whether during theevolution of living substance upon the earth organisms may nothave existed at some earlier time, in which the whole bodyconsisted of a single homogeneous substance, and no separation intodifferent substances had yet taken place. If such organisms ever
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Fig. 9.—Structure of various Bacteria. (After Biitschli.) a, Bacterium lineola, normal and under-going division. 6, Spirillum unclula. c, Bacterium from stagnant water. existed, they could be ranked in comparison with real cells as cytodes,as Haeckel terms non-nucleated elementary organisms. Notwith-standing them, it must be granted that there belongs to theconception of the cell at present, not only a single homogeneousmass, the protoplasm, but also a substance differing from it, thenuclear substance. Accordingly, Max Schultzes morphologicaldefinition would be widened as follows : The cell is a lit ofprotoplasm containing a distinct nucleus. If the protoplasm be examined with strong magnifying powers,in many cells other distinct constituents besides the nucleus arefound embedded in the protoplasmic ground-substance. In manycells oil-droplets occur, in others pigment-granules, in plant-cellsstarch-grains, etc.; but all these bodies do not occur in every kindof cell: they are special