370 MUCUS, 



small, fibrous flakes, interspersed with mucus- or pus-corpuscles. 

 These bodies occur in the expectorated mucus in dipbtheritis, 

 pneumonia, Bright's disease, dysentery, and similar affections of 

 the mucous membranes. In these cases blood-corpuscles are also 

 found to be present. 



When the inflammation of the mucous membrane has ceased, 

 and an exudation of a croupous nature is no longer separated from 

 the canal, certain changes generally occur, which in the ordinary 

 course of the process give occasion to the formation of pus- 

 corpuscles, and during the slower resolution of the exudation, tend 

 to the development of the inflammatory globules or granular cells. 

 Histology shows us that these morphological elements vary con- 

 siderably in size and form. We would here, however, draw atten- 

 tion to the fact, that a species of such granular cells occurs in the 

 mucus, and more especially in the bronchial mucus, without having 

 been preceded by any croupous inflammation of the mucous mem- 

 brane. (They occur, for instance, in the tenacious, thick mucus, 

 which is expectorated in the chronic bronchial catarrh of aged 

 persons.) Under such circumstances, there is only a small 

 quantity of mucous juice in addition to the granular cells and 

 masses, and rarely any other morphological elements ; the granules 

 of the cells are in general much larger than those of the usual 

 inflammatory globules, and resemble the nervous tissue in their 

 strong refracting power. In many respects they bear a resem- 

 blance to the corps granuleux of the milk. In addition to these, 

 there occur concentrically striated corpuscles, which often present 

 the size and form of the granules of potato starch, and greatly 

 resemble them. They are probably identical with Hassal's cor- 

 puscles, found by Henle* under similar conditions. 



It is well known that such sputa are often of a grey, or sooty 

 colour, exhibiting in many cases steel-grey, highly glistening 

 cilia, which are visible to the naked eye. These cilia may be 

 readily isolated by a needle or scalpel, and when brought under the 

 microscope the appearance they present is simply that of closely 

 crowded granular cells of the kind above described, except that 

 they exhibit no trace of pigment-molecules, or of black, or dark 

 coloured masses. I do not know how to explain this phenomenon, 

 except on the supposition that all the light has been absorbed by 

 the densely crowded and strongly refracting cells, in the same 

 manner as we observe that many metallic sulphides which appear 

 black when observed in masses by the naked eye, exhibit nothing 

 * Zeitschr. f. rat. Med. Bd. 7, 8. 411 



