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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![of which spirals are composed*.—The pellucid centres of the rings are left as elements of future offspring, to assume the form of spirals when their progenitors the old spirals as contractors are worn out.] What has just been referred to as seen of the mode of origin of the muscular fibril, I would now apply in considering its mode of reproduction. Thus the flat particles in fig. 4 a I apprehend to be in a state resembling or approaching that of rings. They are, in fact, bodies of the same form as mammiferous blood-discs, fig. 7^ a. Each has its pellucid centre or nucleolus, which, when the outer part assumes the spiral form, is left behind—a line of such nucleoli being the foundation of future offspring. Now I have no doubt that a, fig. 4, passes into a twin spiral in one of the ways just described. If in the first way, it pro- bably undergoes longitudinal separation into two single piles such as that in fig. 3; and then each pile forms a single spiral, which by longitudinal division becomes a double one. But if a, fig. 4, assumes the spiral form in either of the two other ways, it undergoes no longitudinal separation, and it forms but one twin spiral. It is obvious that the bodies df fig. 2, pass into the bodies bd in the same figure. The question is : what is the condition of bd ? Prof. Allen Thomson believes it to be double. I am of the same opinion. Even he admits it to present “ very much the appearance of a spiral.^^ And here also agreeing with him, I would direct attention to a change in the direction of the transverse line in the clear spaces, which direction in bd crosses that of the transverse line in df. It may therefore be that df, fig. 2, consists of two strata of particles, which particles come to alternate with, or overlap one another, as at B in fig. 6; and that further changes, such as those just described, produce an approach towards the completion of a twin spiral in fig 2 bd. Whether, however, an approach towards the completion of a twin spiral is or is not exliibited in the fibril seen by Prof. Allen Thomson and myself, and delineated by him in fig. 2 bd, I cer- tainly saw a twin spiral at the upper end of the fibril in fig. I. This figure I published in the Edinburgh New Philosophical Journal for October 1843, plate 5. fig. 2t- And as it exhibits three states, viz. that of quadrilateral partieles (c), division and dislocation of these {b), and then as a continuation of the latter * Phil. Trans. 1842, plate 10, fig. 126. I also showed, by the action of acetic acid, that spiral filaments are made uj) of particles. (Phil. Trans. 1842, plate 8, fig. 68.) t It represents a young fibril of muscle from the ventricle of a frog’s heart; drawn as magnified 600 diameters.](https://iiif.wellcomecollection.org/image/b22367676_0005.jp2/full/800%2C/0/default.jpg)
