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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![fig. 2; and in Muller’s Archiv for 1850*. When subsequently examining^ along with the Professor, a preparation sent me by Dr. Dobie, we found several of the states in fig. 4, which fully confirm and extend the observations now referred to as recorded by myself in 1843 and 1850f. For this drawing also (fig. 4) I am indebted to the kindness of Prof. Allen Thomson. It needs no description, affording unquestionable evidence of division and subdivision—changes which observers have overlooked, or at least in their consequences disregarded. These changes, with those seen in fig. 2, and with what I am about to state, furnish the explanation he requires. There fii’st exists a line of bodies comparable to germinal spots. Each spot divides into halves, and then each half into four parts; so that each spot comes to consist of eight particles, which eight particles lie in two strata—four in each. This is shown by fig. 5 (also from nature, and drawn by Prof. Allen Thomson), the par- ticles in outline representing the upper, and the shaded particles the lower stratum. Dislocation takes place, a change imme- diately following the division into halves. Of dislocation an example is afforded by fig. 2 ikl, which presents a side view. As dislocation proceeds, there arises in the clear space an appearance which we call a transverse line. Of this line no satisfactoiy ex- planation has yet been given. My belief is that it results from particles belonging to the stratum not in focus. This, I think, is shown by b and c in the drawings from nature, fig. 4, where it is no longer a mere line that is seen, but there have come into view particles not differing from those of the stratum that is in focus. In harmony with this opinion is the following remark by Prof. Allen Thomson, written by him opposite the drawing from nature, fig. 5, viz. “ The transverse line in the clear space is seen when the lower side is in focus; and coincides exaetly in the specimen figured with the margin a of the square particles when the upper side is in focus.”—The line of particles b, fig. 4, affords an instance of longitudinal separation, exhibiting one half of such a line as that at c in the same figure. There can be no doubt that in these lines we see the smallest elements dis- cernible with our highest magnifying powers.—The line a in the same figure (fig. 4) appears to represent a state corresponding to that of the line b; but with this important difference, that in * Taf. XVII. fig. 29, See also Pliil. Mag. for August 1852, Plate I. fig. 6. t Changes such as those in fig. 4 are obviously intimated by the “ cru- cial mark ” at h in fig. 2. Concerning this crucial mark, the Professor, in a letter I have since received from him, remarks :—“ This was well given, if I remember right, in Dr. Dobie’s paper.” [Published, I hear, in the Annals of Natural History for Februan' 1849 ; but I have not seen it.— M. H.]](https://iiif.wellcomecollection.org/image/b22367676_0003.jp2/full/800%2C/0/default.jpg)
