THE NOSE. 781 



epithelium is not ciliated, of which I have most fully satisfied myself, 

 not indeed in Man, in whom I have never yet met with the epithelium 

 of the true olfactory region in a perfect condition, although the ciliated 

 epithelium occurred frequently enough still in a state of vibration, but 

 in the animals just named. It is also much thicker ', so that in the 

 Sheep, in which the ciliated epithelium is 0-03 of a line, it measures 

 0-05, and in the Rabbit, the one is 0-04, and the other 0-07 of a line 

 thick. Notwithstanding this thickness, which is considerable for a 

 mucous membrane, it is remarkably delicate and soft, and is so much 

 affected by almost all reagents as to allow of its being studied only 

 with considerable trouble. According to my observations, it should be 

 described as a squamose cylinder -epithelium ; at all events, in opposi- 

 tion to Todd and Bowman, I always find as its outermost layer, one or 

 two strata of slender, vertical cells, 0-005-0-007 of a line long, whilst 

 it must be allowed that, more deeply, spherical elements, of 0-003- 

 0-004 of a line, alone appear to exist. All these cells have minute, 

 round nuclei, usually pale, finely granular contents of a brownish hue 

 in the deepest layer only in the Rabbit and Dog, and such delicate 

 membranes, that in water they instantly burst. Although the ciliated 

 cells of the nasal fossce are much more readily affected by water than 

 those of other situations, this is true to a much greater extent as 

 regards the cells of the olfactory region ; and the destructive effect of 

 the filling of the nasal cavities with water (E. H. Weber) and other 

 fluids is thus easily accounted for, as well as, on the other hand, is the 

 ready transition of volatile substances through the epithelium rendered 

 intelligible. For the moistening and protection of this epithelium 

 throughout the region in which it exists, it is furnished with a great 

 number of the " glands of Bowman," which is the more remarkable, 

 because the immediately contiguous, ciliated mucous membrane is but 

 scantily supplied with glands, or is wholly without them. These glands 

 are simple cylinders, either straight or slightly convoluted at the lower 

 end, and O'08-O-l of a line in length, or elongated pyriform follicles, 

 situated principally between the larger branches of the olfactory nerves, 

 in crowded rows, in part, however, more isolated, as at the lower 

 boundaries of the olfactory region. They most nearly approach cer- 

 tain forms of the Lieberkuhnian glands, and the sudoriparous glands of 

 the foetus. I have never yet noticed divisions of the follicles, although 

 it is very possible that I may have overlooked them, since these organs 

 are extremely delicate, and easily altered. Their canals, 0-014-0-025 

 of a line wide, are lined by a beautiful, simple epithelium, compose^ of 

 rounded polygonal cells, 0-006-0-008 of a line in size, containing more 

 or fewer yellowish or brownish pigment-granules, to which is due the 

 varying color of the olfactory mucous membrane. Their excretory 



