four-a varying number of smaller ones were several times seen. The nucleoli of such dark-contoured nuclei have attached to them fine radiating spokes extending to the periphery of the nuclei; this is surrounded by a light seam through which go a number of spokes connecting with a network extending through the whole corpuscle. Blood-corpuscles with such nuclei did not materially change their form even when the temperature rose to 95° F.; only occasionally a hyaline protrusion appeared at the periphery, which gradually enlarged, but showed no structure, except that sometimes very small vacuoles were recognized in such a protrusion, which seemed to be bounded by a more dense, slightly shining substance. Hyaline cartilage has hitherto been looked upon as showing characteristically, corpuscles or so-called “cartilage-cells” imbedded in a homogeneous matrix or intercellular substance. But, if a prepared section of hyaline cartilage (taken, for instance, from the condyle of the femur of a middling large rabbit Immediately after death, and moistened with a solution of salt, 1 part to 200 parts of water, or with serum of the blood) be examined with high magnifying power, many of the corpuscles show a structure entirely similar to that just described as exhibited by the colorless bloodcorpuscles of man. If the nucleus of the cartilage-corpuscle be visible, it appears either homogeneous or composed of a dense meshwork of living matter. From its periphery proceed fine conical thorns which lead to a meshwork pervading the whole corpuscle, the threads of which form; at the points of intersection, thickenings, granules, or small clumps of living matter. In the lighter-looking narrow seam, existing between the corpuscles and the surrounding matrix, we may also recognize fine threads which go from the periphery of the corpuscle and are lost to the view in the matrix. On examining such a fresh preparation upon the heated stage, we recognize, at a temperature of from 86° to 95° F., a continual but very slow change in the living matter of those cartilage-corpuscles which distinctly show the network: the points of intersection of threads move nearer together or go further apart, sometimes a few granules lying close to each other unite into one little lump, so that the threads between them disappear, then the latter reappear, lengthen and shorten; and this change in the form. of the interior network continues for some little time, and without any perceptible influence upon the form of the corpuscle as a whole. Careful examination of the matrix reveals throughout its whole extent the existence of a very delicate, more or less distinct network of living matter; and in many instances the connection of the threads proceeding from the corpuscles with this delicate network can be traced. To show the structure of both the cartilage-corpuscles and the matrix still more plainly, we may resort to the method of tinction of preparations by nitrate of silver and chloride of gold, as well as the examination of cartilage during normal calcification, and in its inflamed conditions. It is well known that chloride of gold stains living matter dark violet, while nitrate of silver acts upon the matrix, and, by darkening it, makes the living matter appear of a light color or colorless. The appearances obtained thus complement each other; and the network proceeding from the corpuscles and ramifying all through the matrix, is seen, with the same magnifying power, as constituted by violet threads and granules in the first case, and by white processes or empty spaces in the second case. (See Figs. III. and IV.) As the deposition of lime salts takes place only in the matrix, the living matter itself remaining free, careful examination during such depositions, especially in cases of artificially produced inflammation, also brings to view the fine network of living matter traversing the matrix. Observations analogous to those of the living matter of cartilage have been made in regard to every tissue in the body. Thus, for instance, on examining smooth muscular fibres, fresh or in preparations treated with chloride of gold, we can convince ourselves that from each spindle-shaped body a number of thorns proceed which traverse the surrounding cement-substance and communicate with thorns of neighboring spindle-shaped bodies. Whenever the oblong nuclei are visible, fine spokes are also seen to radiate from them into the surrounding network of living matter. So, also, does the examination of striated muscle demonstrate the same disposition of the living matter. Heitzmann has shown the correctness of the observation published by E. Brücke," "that the sarcous elements do not exist in the living muscle as permanent unchangeable masses, but are groups of molecules which during death, as it were, arrange themselves into variously formed columns:"-" I Untersuchungen über den Bau der Muskelfasern mit Hülfe des polar. Lichtes. Denkschrift der Wiener Akad. d. Wissensch. Bd. xv., p. 76. can recognize," says Heitzmann,1 "in living striped muscle nothing else than in living protoplasm in general, namely, granules and heaps of living matter formed by granules-sarcous elements-and between these a non-contractile intermediate substance." Each granule and each sarcous element can be seen to be connected with its neighbors in all directions by means of fine, grayish threads, which traverse the intermediate substance in both vertical and transverse directions. (See Fig. VI.) And wherever muscle corpuscles, the so-called "muscle cells," are seen, delicate conical spokes can be made out proceeding from the periphery of each of these, passing through the narrow light seam around the corpuscle, and communicating with the neighboring sarcous elements. The connections here described can, of course, be seen more plainly in preparations stained with chloride of gold. Nerve tissue shows the same things, viz., granules and larger accumulations of living matter connected by innumerable delicate threads. The spokes or thorns within the ganglion corpuscles had been described by a large number of previous observers, but they had been looked upon partly as belonging to the structure of the corpuscle and partly as coagulation products. They are no more and no less than the connecting threads which occur in cartilage corpuscles, and, in fact, in all living matter. Fine threads can also be seen coming from the periphery of the ganglion corpuscles, and also from all nerve fibres into the surrounding light seam. As to epithelial tissue, Max Schultze has described what he called "thorned cells" (Stachel und Riffzellen) more than ten years ago as a normal occurrence in pavement epithelium of the skin, lips, of the oral and lingual mucous membrane, and of the conjunctiva palpebrarum.3 The thorns are fine processes from an epithelium element, which traverse the light seam of the cement substance to reach neighboring elements. The thorns are conical, and two coming from neighboring elements meet with their points, or sometimes in the cement substance. (See Fig. V.) Careful treatment by nitrate of silver reveals fine light interruption in the dark brown cement substance corresponding to these thorns, while gold tinction shows a number of violet threads passing through the un 'Sitzungsbericht der k. Akad. der Wissensch. iii. Abth. Mai-Heft, 1873. Bd. lxvii., p. 12. ? See Julius Arnold, Ein Beitrag zu der feineren Structur der Ganglienzellen. Virchow's Archiv, Bd. 41, 1867. Centralblatt f. d. mediz. Wissenschaften, 1864. |