THE NOSE. 417 



the larynx (fig. 311 2 ), measuring, in some places, 0*018 — 

 0020'" in thickness, and in others as much as 0'042 /// . In Man 

 it presents pale, fine- granular cells, of which the outermost 

 ciliated ones attain a length of 0'03'", and in animals produce 

 a current running from before to behind. To this succeeds, a 

 true m. mucosa, wholly without elastic elements, or at all 

 events very scantily supplied with them, and composed chiefly of 

 common connective tissue. In the proper nasal fossae there are 

 imbedded in this membrane very numerous larger and smaller, 

 racemose mucous glands of the usual kind, with gland vesicles 

 of 0*02 — 0-04"', so that, in places, especially at the borders of 

 the septal cartilage, and on the inferior spongy bones, it presents 

 a thickness of 1 — 2 /// . The thickness of the mucous membrane 

 of these regions, however, does not depend upon the glands 

 alone, but also, especially at the border and posterior extre- 

 mity of the inferior spongy bone, upon abundant, almost 

 cavernous venous plexuses in its interior. In the accessory 

 cavities, the glands are almost wholly wanting, and I have as 

 yet only occasionally found them in the antrum Highmori, 

 where their excretory ducts and gland-vesicles are sometimes 

 dilated into cysts containing mucus, J ,w in diameter. Except in 

 these places, the mucous membrane of the accessory cavities is 

 extremely delicate and inseparable, as a distinct membrane, 

 from the periosteum lining them ; and the same may be said of 

 it in the nasal fossse themselves, particularly in the glandular 

 parts, notwithstanding the intimate connexion of the two. A 

 remarkable appearance presented itself to me in the body of a 

 youth aged 15, (who, as I was informed by Virchow, also 

 exhibited ossifications in the lungs), consisting in the deposi- 

 tion — in the mucous membrane, in all these accessory cavities, 

 as well as in the similarly constituted mucous membrane on 

 the concave side of the spongy bones, immediately beneath the 

 epithelium — of calcareous salts, to such an extent, that its 

 uppermost layer was transformed into a peculiar ossified though 

 still flexible membrane, in which there existed, in places, larger 

 and smaller, often very regularly disposed openings, but no evi- 

 dence of a special structure. Under this layer, which, where 

 well developed, appeared perfectly white, like a membrane filled 

 with air-vesicles, as which I at first regarded it, there always 

 occurred a looser connective tissue with vessels, of which latter, 

 ii. 27 



