Renewed inquiries concerning the spiral structure of muscle, with observations on the muscularity of cilia / by Martin Barry, M.D.

  • Martin Barry
Date:
[1852]
Catalogue details

Licence: Public Domain Mark

Credit: Renewed inquiries concerning the spiral structure of muscle, with observations on the muscularity of cilia / 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.

    23/36 (page 21)
    space presented none. On the nature of these large fragments the author has for the present nothing further to remark, than that they afforded him an invaluable contribution towards the histoiy of development of ciha; for of that development they presented with distinctness a very early stage. The minute cells in theu' interior seemed destined to give origin to ciha, which here and there, fig. 29, were seen to have been already formed and to have burst through the membrane of their cells. One of these, the interior of which was seen with rare distinctness, is represented on a larger scale in fig. 30. The young cilium here drawn consisted of two spirals, within the winds of which was a pellucid substance corresponding to that which the author above and elsewhere has termed hyaline. At the extremity the two spirals passed into one another, and were bent over hook-like towards one side. At the base they separated, to bestride, as it were, the contents of the cell in which the cilium had been formed*. Perhaps these two separate thi'eads may be considered as the I'adical ends of the cilium, in which growth fii-st of all takes place somewhat in the following manner:—The extremity of each of these two threads draws into itself new substance from the nucleus of the cell. And now as the ciUum is alternately in the states of twisting and untwisting, it gi-adually spins up into its substance those after-threads, and in this manner elongates. Drawings are then given of stages following those just de- scribed, of which figs. 31, 32, 33, and 34 present a selection. These different appearances evidently denote different degrees of development. [CoiTcsponding differences were noticed in theii- movements. None of them, however, were in a perfect state. For the movements of even the most advanced were awkward, showing them to be, as it were, still in their apprenticeship.] Now to all of these cilia, making allowance for differences in the degree of development, may be applied the description just given of fig. 30; though it is only here and there that a trace of con- nexion with the cell, such as that in fig. 30, can be distinctly seen. The author thinks that no observer can attentively ex- amine such cilia without seeing, as he did, that each of them consists of a double spiral thread, having therefore a structure like that of the musciilar fibril, and thus estabhshing his posi- tion No. 1. The broad cilia of which examples have been given in Beroe and other ciliograde Mollusca,—where, instead of cilia of usual form and arrangement, there are found rows of broad flat flaps each of which is said to consist of a row of single ciha,—appear to * \U will be observed, that each of these separate threads is twisted on itself.]