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.

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    muscle from the Flea, in which, from its enormous leaps, some- thing similar would he thought be found. The author accord- ingly examined some of these, and had the satisfaction to find in them a degree of muscular relaxation even higher than that he had observed in the grasshopper. In the two figures, fig. 16 and fig. 5, the parts in fig. 16 marked b, b, correspond to V, V in fig. 5. From a comparison of these two figures, it will be at once seen how the extended b, b in fig. 16, pass in contraction into the narrower b', b', fig. 5. Similar conditions no doubt exist in other animals, but perhaps nowhere are they more I'e- markable and constant than in those just mentioned. The observation may possibly induce some to bestow their attention upon this subject when examining leaping insects as well as other animals. The author repeats a drawing he gave in the Phil. Trans, for 1843, of an arteiy fi-om the pia mater of the Rabbit, fig. 17, of which the following is an explanation :—a, longitudinal muscular fibrils, represented merely by rows of dots, except a single one on the left side in which is shown the double spiral; b, outline of a fibril surrounding the longitudinal ones; c, double spiral structure of 6; d, blood-corpuscles, for the most part young aud very small; e, a line denoting the inner membrane of the artery. He then gives a figure, fig. 18, representing more distinctly the double spiral structure of such a fibril as b in fig. ] 7. His observations on the history of development of muscle are given in detail, with many illustrative di-awings; but as only a part of the latter can be given in this abstract, it is not intended to offer here more than the substance of the principal facts he observed, which were as follows:— Cells having arranged themselves as at a, fig. 19, and their membranes having passed through the states b and c in the same figure, and a tube having been thus formed (stages known to other observers), columns of compound cytoblasts are seen within the tube, fig. 20 b,c; which cytoblasts have descended by divi- sion from the nuclei of the primitive cells, fig. 19 a. (The com- pound cytoblasts in these columns are arranged with such regu- larity as to produce, and explain the nature of, the strine seen by Schwann, fig. 20 a.) The membrane of the tube disappears, not forming, as Schwann thought, a permanent sarcolemma; and the columns of compound cytoblasts having passed into coils of cells, fig. 13 a, a spiral is formed of tliem, as sho\TO by the dia- gram b in the latter figure. A central row of ccll-germs is left for the formation of future spirals; and the spiral first formed divides, and, as above shown, passes into membrane—the fii'st