Remarks on Quekett's Histology, On Kölliker's Human histology, and on the physiological importance of the nucleus of the cell / by Martin Barry, M.D.

  • Barry, M. (Martin), 1802-1855.
Date:
[1854]
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Licence: Public Domain Mark

Credit: Remarks on Quekett's Histology, On Kölliker's Human histology, and on the physiological importance of the nucleus of the cell / by Martin Barry, M.D. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    nuclei arranged with great regularity in lines.^ In a later stage, such nuclei had become composed of smaller ones.^ In a stage still i later the compound nuclei had elongated, so that the smaller nuclei ' of whicli they consisted were arranging themselves in lines to form ' the fibres of the lens.*^ One of these lines is comparable to one of | the processes we have been considering. And what I have just said , of the material split up, of the way in which it would seem that the j splitting up occurs, and of the investment, I would apply here, as j well as to the formation and reproduction of all other organic fibre j where a splitting up occurs, including woody fibre.* j Certain nerve- cells furnish examples of bodies having a fusi- j form, etc., shape, which I believe to be nuclei and not cells. I am \ desirous of bringing these under the notice of observers on account ' of the physiological importance of the nucleus, and especially that j of the nucleolus. For if such nerve-cells are still nuclei, it is part ; of a nucleus and not merely cell-contents and a cell-wall that enter I into the formation of theii' processes. And if such nerve-cells are ] still nuclei, the pellucid body they contain is a vesicular nucleolus, j no doubt continuing to perform its all-important functions, though \ in what way we have yet to learn, or perhaps may never know. i In the tadpole, I investigated minutely the mode of origin of the epithelium and pigmentum nigrum in the tail, 'and that of the pig- ! mentum nigrum in the eye; and refer to drawings I gave^ as i showing stages earlier than those of pigment figured by Quekett. | My draAvings of pigment, I think, explain the mode of origin of j what he lias well described in stages more advanced. j The black granules of Quekett, in pigment, I found to have 1 their origin in the smaller nuclei, which the original nucleus gives off j in stages earlier probably than those described by him.^ \ Professor Quekett remarks:— In some plants, and especially in the Canna bicolor, the spiral vessels ai'e remarkable for the occur- rence of longitudinal as well as spiral fibres. (Lc. p. 98.) And he illustrates this by fig. 86, c, d, e,f,<j, h. I have already stated my conviction that the spiral fibre in spiral vessels is given off by the nucleus, and, indeed, that all the forms of vascular tissue are refer- , rible to altered nuclei. Now, in plants such as the Canna hicolory presenting longitudinal as well as spiral fibres, it appears to me that 1 analogy points out the following as the mode of oi'igin of the fonner. ' The longitudinal fibres occupy in the vessel a position internal to ; ' Pliil. Trans., 1841, PI. XXIV., fig. 14.5 to 148. ^ Ditto, fig. 14!). ! * Tliis was in a large tiilie formed by coalescence of euibryoriic cells. Phil. j Trans., 1841, PI. XXIV., fig. 1.50. I * See my observations on the mode of reproduction of flax. Phil. Ti'ans., ' 1842, p. J05, and figs. 75, 70, 113, etc. » Phil. Trans., 1841, Plate XXI. •* For such earlier .stages see Phil. Trans., 1841, Plate XXI., figs. 93, !)0,!)!. See also my drawings of the elements of connective tissue, referred to in a preceding '