Volume 3

Manual of human and comparative histology / edited by S. Stricker ; assisted by J. Arnold [and others] ; translated by Henry Power.

Date:
1870-1873
Catalogue details

Licence: Public Domain Mark

Credit: Manual of human and comparative histology / edited by S. Stricker ; assisted by J. Arnold [and others] ; translated by Henry Power. Source: Wellcome Collection.

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    upper surface and tlie sides present low perpendicular folds, i.e., folds running parallel to the axis of the papilla, with intervening furrows. He also observes that these furrows are completely filled with epithelium, so that the surface of the papilla is everywhere perfectly smooth, and exhibits no trace of the subjacent inequalities. The epithelial layer is considera'bly thicker upon the upper surface and that portion of the papilla which is not protected by the circular wall, than upon the protected lateral portions ; but even in the former situations it is far thinner than upon the remainder of the surface of the tongue. The epithelium is also very thin upon the external wall of the vallecula. The gustatory bulbs are situated in the thin epithelium at the sides of the papilla, and indeed there usually form a zone that extends from the bottom of the fossa upwards to about the level at which the papilla is no longer protected by the lateral wall (Schwalbe). The zone, like the wall, entirely encircles the papilla. If the fossa be deep, as in the Sheep and Pig, the zone is broad ; if, as in the Horse, it be shallow, it is narrow. In Man, however, even when the fossa is deep, the upper half of the lateral wall of the papilla appears to be destitute of gustatory bulbs (Schwalbe). The number of the gustatory bulbs is very great, since as a rule they stand in close contiguity to one another, and most so in Man, where, according to Schwalbe, they are in absolute contact. Schwalbe estimated the number present in one papilla of the Sheep, of moderate size, at 480 ; in one from the Ox, at 1,760 ; in the Pig, which only possesses two circumvallate papillae, each has about 4,760 bulbs. This would give a total number of bulbs in the Sheep, of 9,600; in the Ox, of 85,200 ; in the Pig, of 9,520. In Man and in the Dog, according to Schwalbe, and in the Rat and Rabbit, according to Loven, a few bulbs usually appear to be scattered on the outer wall of the vallecula, or that which looks towards the Fig. 270. Fig. 270. Transverse section through a papilla circumvallata of a Calf. Showing the arrangement and distribution of the gustatory bulbs. Magnified 25 diameters.