Microscopical morphology of the animal body in health and disease / by C. Heitzmann. With 380 original engravings.
- Carl Heitzmann
- Date:
- 1883
Licence: Public Domain Mark
Credit: Microscopical morphology of the animal body in health and disease / by C. Heitzmann. With 380 original engravings. Source: Wellcome Collection.
Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.
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![of tlie presoneo of a inembnino, whetlier prei'xisterit or artificially produced. In t'rt'sh blootl of ainphiinna he has observed colored blood-coi'puscles with a j;reoiiish border, indicating the existence of a thin layer at the surface, dif- ferinj;, if not in ch(>niical coniposition at least in density, from the substance of the disks. He lias freqiU'utly met with specimens of Idood-corpuscles, on which, by a contraction of the protoplasm I'ejjresentiiig the gi'eater ])oition of the whole body, the jiellicle in (piestion appears separated fi'ora the latter. Once he saw a fragment of a corpuscle on which the membraneous layer was seen projecting on the torn surface ; and at another time he found a fresh blood-corpusch» of the anipliiuma on which the membraneous layer had appai'- ently l)urst and retracted, leaving a portion of the underlying malerial, the protoplasm, exposed. He says: The changes taking place in these blood- corpuscles, wlien treated with the solution of the hydrate of chloral, are very interesting and important; as they manifestly show the existence of the mem- braneous hiyer of these bodies, such as I have described it. Thus, after the solution has been applied, the protoi)lasm of the blood-corpuscle, without much or any alteration of form, gracbially contracts upon the nucleus. As the result of this contraction, it becomes entirely separated from the membraneous layer, which manifests itself in the form of a delicate double contour. The inter- space left between the contracted protoplasm and the double contour repre- senting the membraneous layer is very considerable, as will be seen from the di-awings, and, it seems to me, should be sufficient evidence to prove the existence of such a layer to an unbiased mind. In the colored blood- corpuscles of the frog, he has also seen a distinct stratum, or membraneous layer. The colored blood-corpuscles of man show a double contour under vari- ous circumstances and conditions, indicating the existence, if not of an enveloping membrane, at least of a membraneous layer on its surface. As one proof, Schmidt recommends the experiment of pressing down, by means of the point of a forceps, a small round covei'ing-glass upon a very small drop of fresh himian blood placed upon the slide, with the object of compressing or crushing the Itlood-corpuscles as far as possible. Carefully examined with a first-class objective of sufficient amplification, it will be foiuid that they have not run into each other; but that, on the contrary, the outlines of almost every individual may be discerned, however distorted they may be. Almost all investigators nowadays agree that the colored blood-corpuscles of birds, reptiles, amphibia and fishes liave a nucleus ; while in those of man and other mammalia, except in developmental forms, a nucleus does not occur. On this difference, Gulliver has founded his division of all vertebrate animals into pyi-ensemata and ai^jTensemata.* Biit the existence of a nucleus in living corpuscles of oviparous vertebrata has been denied on the one hand; while, on the other, the opinion has been advanced that the mammalian red coi-puscles, as well as those of other vertebrata, are in reality nucleated, Proceertiugs, -with otlier Microscopical liitcllijicucc. Lomlon, vol. i., No. 2 (Ma}-, 1878), pp. 57-78; No. 3 (July, 1878), pp. 67-120. * Lectures on the Klood ot Vertebrata, f. c. ; in Journal of Anatomi/ and Physiology, vol. ii.; Proceeiiiiigs of the Zoological Society of February 25, 18(52 ; and Hniiteri;ui oratiou. 1863, referred to in Observations on the sizes and shapes of the red corpuscles of the blood of vertebrates, with drawings of tlieni to a uniform scale, and extended and revised tables of measurement. Proceedings of the Zoological Society of London, for the j'ear 1875, Part UI., 1.. 47'.l.](https://iiif.wellcomecollection.org/image/b21219163_0111.jp2/full/800%2C/0/default.jpg)
