ITS MORPHOLOGICAL CONSTITUENTS. 369 



tansky,* that the colloid matter of cysts of the thyroid gland, and of 

 the liver, kidneys, and ovary, may be converted into a substance 

 very similar to, or even identical with the mucus, no epithelium 

 being present in it. In the same manner as permanent carti- 

 lage may be converted into glutin, the gelatin of Wharton is readily 

 converted into mucus (Virchow).f 



We will now briefly consider the various histological elements 

 which are blended with normal and abnormal mucus. 



Normal mucus is never free from the epithelium of the mucous 

 membrane from whence it has originated, and may, indeed, be said 

 to consist almost entirely of epithelium, which appears to be only 

 held together by means of a pellucid juice. This is as much the 

 case with the mucous membranes which are invested with pavement 

 epithelium, as with those which exhibit the cylindrical or ciliated 

 structure ; the cilia of the latter are, however, in general thrown 

 off, so that we can rarely find perfect ciliated epithelium even in 

 abnormal secretions. 



According to the assertions of several observers, mucus-cor- 

 puscles do not occur in normal mucus ; but some of these bodies 

 may always be found on carefully examining the expectoration from 

 the mouth, the normal mucous cloudy sediment in the urine, or 

 the solid excrements. Although the mucus-corpuscles, which 

 have justly been regarded as abortive epithelial cells, exhibit no 

 distinct differences, either in a morphological or even in a micro- 

 chemical point of view, from the ordinary pus-corpuscles ; yet it 

 cannot be denied that it requires the aid of water, or acetic acid, to 

 bring into view the nuclei both of the normal and sparingly dispersed 

 mucus-corpuscles, and of those corpuscles which are secreted from 

 the mucous membrane during catarrh ; in this case, however, 

 the nuclei present one or more fissures. The mucus in blen- 

 norrhceal discharges contains little epithelium, and consists almost 

 solely of mucus-corpuscles which are suspended in a greater or 

 less quantity of viscid intercellular fluid. No essential difference 

 can be observed between it and pus, in so far as either the collective 

 fluid or the cells are concerned. 



In the so-called exudative, or croupous inflammations of the 

 mucous membrane, we constantly find fibrinous coagula, which 

 frequently bear the impress of the cavity, or canal, from which 

 they have originated; and at other times appear in the form of 



* Ueber d. Cysten. Wien, 1849, S. 20, reprinted from the first volume of 

 Denkschr. d. math, naturwiss. Classe d. kais. Akad. d. Wissensch. 



t In a Private Communication. , 

 VOL. II. 2 B 



