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DIVISION OT NUCLEI. MUSCLE.
which Robin has described in the marrow of bones. This is something quite peculiar which looks extremely like the commencementof a real new-formation, only that new-formations in the ordinary sense of the word are not limited to single cell-constituents. Besides we must bear in mind this very important fact, that exactly the same limitation takes place in the earliest embryonic development of muscle, in the course of the first growth of the primitive muscular fasciaculi. For this is the manner in which muscle originally grows. If a growing muscle be watched, the same division of the nuclei is witnessed, and after groups and rows of nuclei have arisen in it, they are, in the course of growth, gradually thrust farther and farther asunder by the continual increase of the intermediate sarcous substance. Now although a growth in length has not as yet been demonstrated with certainty in a pathologically irritated muscle —I say demonstrated, because there really is a probability that something of the kind may yet be proved to be the case—we must still hold the perfect analogy of morbid irritative processes with the natural ones of growth to be a well-ascertained fact. For the formative act of real growth begins with a multiplication of the centres, inas
Fig. 105. Division of nuclei in primitive muscular fasciculi from the immediate neighbourhood of a cancerous tumour in the thigh. At A a primitive fasciculus, the transverse striation of which is not represented all the way down, with its natural, spindle-shaped extremity f, and incipient multiplication of the nuclei. B. Strongly marked proliferation of nuclei. 300 diameters.
much as the nuclei must, as was long since shewn by John Goodsir, be regarded as the central organs of the cells.
If now, gentlemen, we advance a step farther in these processes, we come to the new formation of the cells themselves. After the multiplication of the nuclei has taken place, the cell may certainly, as we have seen, continue to subsist as a coherent structure, still the rule is, that even after the first division of the nuclei, the cells themselves undergo division, and that after some time two cells are found lying closely side by side, separated by a more or less straight partition, and each provided with a nucleus of its own (Fig. 6, b, b). This is the natural, regular manner in which the real multiplication of cellular elements takes place. Then, the two cells may separate, if the tissue is one which possesses intercellular substance (Fig. 6, c, d); or may remain lying close to one another, in the case of a tissue simply composed of cells (Fig. 27, C). This series of processes, which in their subsequent course lead to a continually proceeding division of the cells, and to the
production of large groups of cells from single ones (Figs. 9, 22), occurs in the adult body just as unquestionably as the result of a direct irritation of the tissues, as the class we spoke of before. If, for example, we follow up a little farther the case which we before considered, of the production of a simple, mechanical irritation by drawing a thread through the parts, we usually observe that the swelling is not simply limited to the enlargement of the existing cells,
Fig. 106. Cells from the central substance of an intervertebral cartilage of an adult. Intracapsular multiplication of cells. 300 diameters.
THE HUMORO- & NEUROPATH OLOGICALDOCTRINES. 311
but that they divide and multiply. Round about a thread, which we draw through the skin, a number of young cells generally shew themselves as early as the second day. The same change may be brought about by the application of a chemical stimulus. If, for example, caustics be applied to the surface of a part, the first thing that happens is that the cells swell up and then, when the process follows a regular course, divide, and begin to proliferate more or less abundantly. Here too we have still to deal with actions which do not exhibit the slightest difference in the real mode of their accomplishment, whether the part be provided with nerves, or destitute of them, whether it contain vessels or not.
Accordingly, we cannot say that any part of these processes appears to be necessarily dependent upon nervous or vascular influence, but, on the contrary, we are in all these cases referred to the parts themselves. The relation of the vessels is not by any means to be explained in the way in which it is ordinarily done; the absorption of matter into the interior of the cells is unquestionably an act of the cells themselves, for we are as yet acquainted with no method enabling us to produce this kind of proliferation in the body, by any mode of experimentation, through the medium of an agency primarily affecting either the nerves or the vessels. The circulation may be heightened in the parts as far as it is possible to heighten it, without the production of such an increased nutrition of the parts as to give rise to any swelling or multiplication of the elements themselves. Those very experiments too upon the section of the sympathetic nerve which I have already mentioned, have, as is well known, proved (I myself have very frequently performed this experiment and watched its effects with this especial object) that an increased afflux of blood may last for weeks—an afflux of blood accompanied by a marked elevation of temperature and corresponding redness, as great, both of them, as we ever meet with in inflammations —without the production of the least enlargement in the cells of the part, or the excitation of any process of proliferation in them. Irritation of the nerves may be combined therewith. But when the tissues themselves are not irritated, when the irritation is not made to act upon the parts themselves, either by the direct application of the irritating matters, or by their introduction into the blood, the occurrence of these changes cannot be relied upon. This is a most important argument from which I draw the conclusion, that these active processes have their foundation in the special action of the elementary parts, an action which does not depend upon an increased afflux of blood or any excitation of the nerves, but which is certainly promoted by them, though it can also continue entirely independently of them, and manifests itself with just as great distinctness in a paralyzed and nerveless part.
In support of these positions I will only add that more recent observations have gradually done away with the whole class of the so-called neuro-paralytical inflammations. The two nerves with which we are almost exclusively concerned in the discussion of inflammatory phenomena, are the pneumogastric and the fifth pair, after the section of which, in the one case, pneumonia, in the other, those celebrated changes in the eyeball have been observed to declare themselves. These observations have now been explained in this way, that inflammations certainly may come on after such sections, but that the real interpretation to be put upon them is, that they manifest themselves in spite of the section? With regard to the pneumogastric it was, as is well known, long since shewn
1 For if, as the neuropathologists assume, irritation produces inflammation through the medium of the nerves, then, when the nerves are cut, all inflammation ought to be impossible.
NEURO-PARALYTICAL INFLAMMATION. 813
by Traube that the paralysis of the ritna glottidis, whereby the entrance of the buccal fluids into the air-passages is facilitated, is the principal source of the inflammation; besides, the more accurate interpretation of the pathological specimens has determined, that a great part of what had been called pneumonia, was really nothing more than atelectasis with hyperemia of the lungs; actual pneumonia may with certainty be avoided, if the possibility of the penetration of foreign bodies into the bronchi is cut off. The same has been ascertained to be the case with the inflammations coming on after the section of the fifth pair, and indeed by means of a very simple experiment. After a number of attempts of the most varied kind had been made for the purpose of removing the different disturbing influences affecting the eye that was deprived of its sensibility, a very simple method was at last discovered in Utrecht for providing the eye with a substitute for its sensitive apparatus; for Snellen sewed before the eyes of animals, in which he had cut the fifth pair, their still sensitive ears. From that time the animals had no more attacks of inflammation, inasmuch as on the one hand a direct protection was afforded to the eye, and on the other the animals were preserved by the presence of a sensitive covering from all traumatic influences. As soon as sensation was re-established, not in the eye itself, but only before the eye, what was really nothing more than a traumatic inflammation was got rid of.1
1 In the text the influence of the section of nerves is perhaps not described with sufficient minuteness. According to the author's views, of which a more detailed account may be found in his Handbuch der spec. Pathologie und Ther. Erlangen, 1854 (Vol. I, pp. 31, 50, 80, 276, 314, 319), the section and paralysis of nerves certainly exercise some influence upon the nutrition of the tissues, although perhaps only an indirect one. The states arising from such causes he has classed together under the name of Neurotic Atrophy. Parts which have in this way suffered derangement in their nutrition, and as a consequence have become weakened, are less capable of controlling the disorders by which they are attacked, and accordingly simple irritation in them readily becomes aggra