Observations on the minute structure and mode of contraction of voluntary muscular fibre : being the abstract of a paper read before the Royal Medical Society, Edinburgh, December 15th, 1848 / by W. Murray Dobie.

  • Dobie, William M. (William Murray), 1828-1915.
Date:
[1849]
Catalogue details

Licence: Public Domain Mark

Credit: Observations on the minute structure and mode of contraction of voluntary muscular fibre : being the abstract of a paper read before the Royal Medical Society, Edinburgh, December 15th, 1848 / by W. Murray Dobie. 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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    tiguous clear space ; in fact, feba* we are not able to say with any degree of certainty, that any portion of a muscular fibril in the mature state is a cell containing fluid, as Mr. Erasmus Wilson believes. 3. That the clear space can be distinctly seen to have a dark hne crossing it transversely and dividing it into two equal parts, and that the dark space also presents a similar division caused by a line which is generally seen of alighter shade than the other parts of the same space, and not a broad black band as is erro- neously represented by Mr. Erasmus Wilson (fig. 6 « & fig. 5 a). 4. That no clear area exists at the edge of the fibrillse extend- ing transversely outwards from the dark spaces, giving the fibrillse the appearance of a chain of nucleated cells, as is repre- sented by Dr. Sharpey and Dr. Carpenter'(fig. 4).JjYliis conclu- sion I have been irresistibly led to by the following considera- tions :— a. The fact that when two fibrillse lie side by side, the edges of the black spaces are in accurate apposition. b. That if this lateral clear area really existed, the fibre would be spotted, or at least marked with longitudinal strise quite as distinct as the transverse ones, which in this case would not be well-marked (fig. 4 a). c. That the edges of the clear space can be seen under a fine instrument not to extend farther laterally than the edges of the dark space (fig. 6 a). [I perceive Mr. Quekett intone of the plates to his recent work on the Micrxjscope \tm- distinctly represented this, though he gives an incorrect diagram to explain an appearance which he represents quite correctly.] d. That the cross-line in the clear space measures exactly the same as the breadth of the dark space, and that it can be di- stinctly seen in favourable cases to touch the edges of the clear space (fig. 6 d). 5. That it seems probable that there exists a homogeneous connecting medium among the fibrillse (fig. 8 « & 6). 6. That the structure of cross-striated muscular fibre is essen- tially the same in all the members of the animal kingdom. 7. That from all I have seen of the structure of voluntary muscle, I am perfectly certain that the appearances presented are quite inconsistent with any palpable spiral arrangement, either in the fibre or fibrillse, as is still the opinion of Dr. Martin Barry. Mr. Bowman's observations ought to have set this point at rest. 8. That the dark spaces become clear, and clear spaces dark, during a change in the focus of the instrument, causing a pecu- liar appearance of movement on the fibrillse (fig. 6 « & 6).