Embryology, with the physiology of generation / trans. from the German, with notes, by William Baly.
- Johannes Peter Müller
- Date:
- 1848
Licence: Public Domain Mark
Credit: Embryology, with the physiology of generation / trans. from the German, with notes, by William Baly. Source: Wellcome Collection.
Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.
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![developed coincidently. For, in the embryonic cartilage of the toad, in which this mode of development occurs, Vogt never could detect either free nuclei or cells unprovided with nuclei; when nuclei were found, they were invariably surrounded by a cell-wall, and when cells were found, they invariably enclosed a nucleus. In explanation of this coincident forma- tion of cell-wall and nucleus, Vogt suggests that probably one portion of the granular matter of the cytoblastema, from which a cell is about to be developed, may collect, centripetally, at the centre, to form a nucleus, while another portion may collect around, at some distance from it, by a centrifugal influence, and there form a cell-wall. Kolliker's * opinion of the mode of origin of cells, founded upon the results of researches on the development of invertebrate animals, differs in several respects from those entertained by Henle and Vogt. For he believes that the so-called primary cell is, as Schleiden and Schwann described, in almost all cases developed around a nucleus, which persists for a greater or less length of time, and that the nucleus also is in most cases formed around a nucleolus. The irregular appearance frequently presented by the nucleus of pus-corpuscles, especially after being acted upon by dilute acetic acid, is not, as Henle supposed, an early character, and an indication of its being originally composed of two or more separate particles—for, at its first formation, the nucleus is invariably a simple vesicular body—but is an after effect, and is due to the nucleus being- divided into two or more new vesicular bodies, each of which may, if carefully examined, be seen to contain a minute particle or nucleolus; and these, he thinks, originate by endogenous multiplication. In a recent essay, H. Miiller ] has advanced an opinion concerning the development of the corpuscles of pus and of chyle, which differs from that of other writers, and from which it would seem that these corpuscles originate in a manner somewhat similar to the third mode of development described by Vogt. He believes that previous to the development of cells the chyle consists of a number of particles, some of which are soluble, others insoluble. In the production of chyle-corpuscles or cells, a num- ber of both kinds of particles become aggregated into a mass; shortly after the formation of which, the insoluble particles collect together in the centre to form the nucleus, while the soluble ones dispose themselves around the circumference, and are transformed into the cell-wall. A very similar process he states to be pursued in the formation of pus- corpuscles. Such are some of the principal observations which have been lately made on the subject of the development of cells. The amount might have been considerably extended by including the remarks of many other * Entwickelungs-geschichte der Cephalopoden, 1844, p. 142. + Beitriige zur Morphologie des Chylus und Eiters, in Henle und Pfeufer's Zeitschrift, b. iii.](https://iiif.wellcomecollection.org/image/b21522145_0360.jp2/full/800%2C/0/default.jpg)
