THE NOSE. 779 



I 



0-024-0-032 of a line thick, a dense cutis of 1-4 with minute unde- 

 veloped papillae of 1-40-1-66 of a line, and fine hairs, as well as by a 

 close adipose tissue 1 line thick, intimately united with the cartilage, 

 containing large sebaceous follicles, extending into the latter, and minute 

 sudoriparous glands 1-10-1-12 of a line in diameter. This external 

 integument, with its sebaceous follicles, and with stronger hairs (vibrissce) 

 also extends a short distance into the nasal fossce, but not quite so far as 

 the point where the cartilaginous portion of the nose terminates, passing 

 imperceptibly into the mucous membrane of the olfactory organ, by 

 which all the remaining cavities are lined, though it does not everywhere 

 present the same conditions. As was discovered by Todd and Bowman, 

 and I can fully confirm, this mucous membrane is subdivided into a cili- 

 ated and a uou-ciliated portion, the latter being limited to the uppermost 

 parts of the nasal fossce, where the olfactory nerve is distributed, and 

 consequently should perhaps be termed the olfactory mucous membrane 

 in the stricter sense, whilst the other might retain the old name of 

 " Schneiderian membrane." 



Upon first viewing the latter, it will be found that, although the epi- 

 thelium vibrates throughout, still that its structure is not everywhere 

 the same, and that we may conveniently distinguish in it the thicker 

 glandular mucous membrane of the proper nasal fossce from the thinner 

 membrane of the accessory sinuses, and of the interior of the spongy 

 bones. The epithelium, in both situations, is squamose and ciliated, like 

 that of the larynx (Fig. 811 2 ), measuring, in some places, 0-018-0-020 

 of a line in thickness, and in others as much as 0'042 of a line. In 

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

 ones attain a length of 0*03 of a line, 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 fossce there are imbedded in this membrane very nume- 

 rous larger and smaller, racemose mucous glands of the usual kind, 

 with gland vesicles of 0-02-0-04 of a line, so that, in places, especially 

 at the borders of the septal cartilage, and on the inferior spongy bones, 

 it presents a thickness of 12 lines. The thickness of the mucous mem- 

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

 but also, especially at the border and posterior extremity of the inferior 

 spongy bone, upon abundant, almost cavernous venous plexuses in its 

 interior. In the accessory cavities, the glands are almost wholly want- 

 ing, and I have as yet only occasionally found them in the antrum High- 

 mori, where their excretory ducts and gland-vesicles are sometimes dilated 

 into cysts containing mucus, J a line 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 ; 



