A main cause of discordant views on the structure of the muscular fibril / by Martin Barry.
- Martin Barry
- Date:
- 1853
Licence: Public Domain Mark
Credit: A main cause of discordant views on the structure of the muscular fibril / by Martin Barry. Source: Wellcome Collection.
Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.
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![the twin spiral («) in the same fibril, I have thought the figure deserving of reproduction here (fig. 1). Along with this figure I published the following remarks, viz. Were filaments formed by each half-nucleus (fig. 1 b) of two adjacent rows to assume the spiral form and interlace, and the filaments of the same row to then unite, we should have the double spiral. [The oblique posi- tion of the two rows of half-nuclei in fig. 1 6 is not undeserving of notice here.]*” It is satisfactory to find, that while the renewed inquiries made known in this communication enable me to explain some details, they do not show that views thus long since published require an essential change. A friend, long accustomed to use the microscope, and gifted with a keen microscopic eye, whom I had convinced of the existence of spirals in muscle, once suggested that the spiral structm’e might be the earlier rather than the fully-developed condition of the fibril, the quadrilateral particles representing its fully-formed state.” Referring him to the drawing reproduced in fig. 1, I was compelled, with almost rude brevity, to say that I should find it about as easy to admit that thread exists before the flax that forms it, or a chain before the links of which it is composed. Consisting as it does of two spiral filaments, the muscular fibril, in its movements between contraction and relaxation, of course presents a variety of forms. And as the microscopic in- quirer into the structure of muscle is sure to have one or more of such forms before him (unless all the muscle in the field of view is in full contraction or complete relaxation), 1 have con- structed models by which the eye may be prepared for these forms. In fig. 6E is shown a very simple method of constructing such a model. At a are two lead wires of equal leugth, which, held parallel and together, were obliquely wound upon a large knit- ting needle, b. The needle having been withdrawn, there re- mained a model of the mature and acting muscular fibril (and indeed of the original form of all organic fibre). So easily did the two wire spirals then change their positions, that on merely rolling the model on a white surface, I saw it present the three varieties of form a, b, c, drawn from nature in fig. 7; which in- clude two states of the single and one of the double cylinder. While, however, from their weight, w'ires of lead have the ad- vantage just mentioned of presenting changes in relative position * Edinb. New Phil. Joinnal, Oct. 1843, p. 214.](https://iiif.wellcomecollection.org/image/b22367676_0006.jp2/full/800%2C/0/default.jpg)
