Recent advances in the physiology of motion, the senses, generation, and development. Being a supplement to the second volume of Professor Muller's "Elements of physiology". / by William Baly and William Senhouse Kirkes.
- Date:
- 1848
Licence: Public Domain Mark
Credit: Recent advances in the physiology of motion, the senses, generation, and development. Being a supplement to the second volume of Professor Muller's "Elements of physiology". / by William Baly and William Senhouse Kirkes. Source: Wellcome Collection.
Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.
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![IN THE DEVELOPMENT OF TISSUES. epithelial coat of the vessel. In the next layer, which forms the so-called internal coat of the vessel, the nuclei remain unaltered. But in the for- mation of the muscular or contractile coat of arteries, the nuclei elongate and arrange themselves in rows in the manner before described. Moreover each row of elongated nuclei appears to appiopnate the adjoining stup of Jggg membrane m which it is imbedded, and the losult is that this membrane breaks up into a number of flat fibres, each bearing upon its surface the row of nuclei after which it was modelled. Organic muscular fibres of other parts of the body are formed after exactly the same plan. In the formation, also, of fibro-cellular or areolar tissue, the nuclei are arranged in rows, to each of which is appropriated a strip of the cytoblas- tema; and each such strip, instead of remaining flat and ribbon-like, as is the case in organic muscular fibre, breaks up into a bundle of parallel longitudinal fibrillae. This is quite opposed to the account given by Schwann* * * § of the development of fibro-cellular tissue. Kolliker,f in alluding to these several transformations undergone by the nuclei, men- tions also, as other instances, the different modes of development of seminal filaments directly from nuclei,]: and the growth of the spines of several invertebrate animals. Arguments in favour of the view of the importance of the nuclei to the growth and well-being of the tissues in which they occur, are furnished also by the phenomena which attend their retrograde, as well as their advancing transformations—their degradation as well as their develop- ment. For it has been rendered highly probable by the investigations of Mr. Paget,§ that in all cases of atrophy accompanied with degeneration of tissue, the nuclei of the degenerated part lose their characteristic proper- ties, or entirely disappear. This is especially the case in fatty degenera- tion (or atrophy) of muscle, of the liver and of the kidney, in all well-marked instances of which, the nuclei, of the fibres in one case, of the hepatic and renal cells in the other cases, have completely disappeared, their place being occupied with fat, in the form of granular matter, or drops of oil. Development of the Blood. It may be desirable here to present some account of the principal ob- servations recently made on the development of the blood corpuscles. Concerning the original formation of these corpuscles in the embryo, the results of nearly all recent investigations tend to shew that, as was stated by lleichert, || at the first appearance of a vascular system they consist, in all vertebrate animals, of nucleated, colourless, granulated cells, identi- * Muller’s Physiology, p. 1646, and fig. 253. + Entwickelungs-gesch. der Cephalopoden, p. 145. J For an account of these modes of development, see p. 41. § Lectures at the Royal College of Surgeons, May, 1847. Lecture V. || Muller’s Physiology, p. 1550.](https://iiif.wellcomecollection.org/image/b21967660_0141.jp2/full/800%2C/0/default.jpg)
