. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. TONGUE 1139 is to be found. In the other forms we saw it continued over the whole compound organ as a thin indusium, covering in and concealing the secondary papillae under its smooth invest- ment, the scales being arranged parallel to the surface; but in the conical and filiform papillas we not only see the epithelium exist- ing in much greater quantity, but over each secondary papilla assuming a vertical arrange- ment, and, after continuing compact for some little distance, breaking up into a brush of hair-like process
. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. TONGUE 1139 is to be found. In the other forms we saw it continued over the whole compound organ as a thin indusium, covering in and concealing the secondary papillae under its smooth invest- ment, the scales being arranged parallel to the surface; but in the conical and filiform papillas we not only see the epithelium exist- ing in much greater quantity, but over each secondary papilla assuming a vertical arrange- ment, and, after continuing compact for some little distance, breaking up into a brush of hair-like processes (fig. 756.), the number coinciding with that of the secondary papillae Where the secondary papillas are few the hairs are few, where they are many the hairs are many, and each hair may be traced down, by following the line in which the epithelium is vertical, to each papilla. In fact, these pro- cesses are true hairs, and only differ from other hairs in being short, uncompact, imperfectly elaborated, and in having the imbrication retroverse instead of directed forwards; and the secondary papillae from which they spring are true hair papillee, differing only from ordi- nary hair papillae in being raised and grouped on a common pedicle instead of sunk in a proper follicle. In some cases the resemblance of these filaments to ordinary hair is very close indeed, as seen in Jig. 758, ; indeed in c Fig. Hair-like processes of filiform papilla, a, Mag. 150, b and c, 100 diameters. the chief difference is in the direction of the imbrication : in some morbid specimens I have seen it even closer. Now this difference in the arrangement of the epithelium on the different papillae in- dicates, I think, a very important physiolo- gical distinction ; in one case we see the sen- tient papilla? covered by a thin layer of a fine epithelium, thinner over them than in the in- tervals between them ; in the other case we see each secondary papilla the seat of a rapid generation of epitheliu
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