780 



SPECIAL HISTOLOGY. 



and the same may be said of it in the nasal fossae themselves, particu- 

 larly in the glandular parts, notwithstanding the intimate connection 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 deposition 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 ex- 

 tent, 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 evidence of 

 a special structure. Under this layer, which, where well developed, ap- 

 peared 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, however, some were also incrusted; and 

 in the deeper parts of the epithelial layer itself, there were scattered, 

 smaller, simple or aggregated concretions, like " brain-sand" in minia- 

 ture. 



The proper olfactory mucous membrane of all the divisions of the 

 organ, occupies only the uppermost parts of the septum and of the 



walls of the proper nasal fossce, where 

 the superior spongy bones are situated, 

 to a distance of about f-1 inch down- 

 wards from the lamina cribrosa. It is 

 distinguishable, even by the naked 

 eye, from the contiguous ciliated mem- 

 brane, by its greater thickness and its 

 color, which is sometimes yellowish, as 

 in Man, the Sheep, and Calf; some- 

 times yellowish-brown or brown, as in 

 the Rabbit and Dog; and, when ex- 

 amined microscopically, it is seen to 

 be bounded by a tolerably well-defined, 

 toothed or undulated border. The 

 differences of the structure depend 

 upon the condition of the epithelium, 

 the occurrence of numerous peculiarly 

 constructed glands, which I shall term 



"Bowman's glands," and upon the relations of the nerves. The 



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FIG. 312. From the nasal mucous membrane of the Sheep; magnified 150 diameters. 1, 

 from the regio olfactoria, transverse section of the mucous membrane : a, epithelium without 

 cilia ; 6, olfactory nerves, with a dividing, pale, nucleated fasciculus; c, one of "Bowman's 

 glands ;" d, its orifice. 2, ciliated epithelium of the Schneiderian membrane. 



