On the artificial production of tubercle in the lower animals : a lecture delivered at the Royal College of Physicians, May 15, 1868 / by Wilson Fox.

  • Wilson Fox
Date:
1868
Catalogue details

Licence: Public Domain Mark

Credit: On the artificial production of tubercle in the lower animals : a lecture delivered at the Royal College of Physicians, May 15, 1868 / by Wilson Fox. Source: Wellcome Collection.

Provider: This material has been provided by King’s College London. The original may be consulted at King’s College London.

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    ingly rare. Once or twice I have seen it in the rabbit; never distinctly in the guinea-pig. The microscopic examination of these growths in the lungs presents the following features. In the first place, there are three main points in which they appear to originate. One of these is around the bronchi, another is around the blood-vessels, and another is in the tissue of the lungs, where no particular connexion can he seen with either bronchi or vessels. Around the bronchi (Plate II. fig. 1, A, B), they seem to extend from little masses of a lymphatic character, which normally exist in the bronchial sheath, and which are abundant in the guinea-pig, and are also stated by Kolliker to exist in the human lung. These granulations in the bronchi consist of masses of cells growing in their sheaths, l-2500th to l-3000th of an inch in diameter, mostly round, but sometimes, when densely packed, showing nothing but nuclei. These cells extend into the surrounding pulmonary tissue, and produce effects which I will dwell on presently. The other place in which they commonly originate is in the perivascular sheaths of the pulmonary arteries (Plate II. figs. 2, 3). Here the growth appears to be nothing more than an accumulation of the cells lining the perivascular canal (fig. 2). The growth may extend for a considerable distance in length along both the peribronchial and perivascular sheaths; and from both these sources of origin a rapid extension ensues into the surrounding walls of the alveoli and smaller bronchi. A thickening of these is thus produced, and apparently by a double mode of growth—by a rapid develop- ment of fusiform cells at the margins, clusters of which are seen passing among the capillaries, and by an increase of rounder cells, which are seen nearer the centre of the new formation. Coincidently with this growth, a change of great importance occurs in the capillaries of the lungs (Plate II. figs. 5, 6, 8). Their nuclei enlarge, and the vessels, otherwise apparently unchanged, contain no more blood; that is to say, no injection will pass into them; and yet their outline is still marked, even in the neighbourhood of these tubercular masses, by lines of nuclei traversing the base of the air- vesicles. This obstruction of the capillaries takes place through very much wider areas than the space apparently occupied by the tubercle. So also with the thickening of the walls of the alveoli. Around the grey granulations, and for a space of three or four times their area, there is a circumference of thickening affecting both the walls of the alveoli and of the smaller bronchi. This appearance is more distinct in the guinea-pig than in many specimens of tubercle in the human lung; but it can be distinctly seen sometimes in the latter, and is a fact of great pathological importance, explaining the increased c 2
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