As noted above, and as may be seen by comparing [Figures 37] and [39], the gland during hibernation, at least in the animals studied, consists of many more alveoli than during the feeding season; this, of course, might not prove to be always the case if larger numbers of animals were studied; the difference in the ages of the animals might have caused this difference in the glands. In the material studied the largest glands from the hibernating animals consist of more than twice as many alveoli as the glands in the feeding animals. As seen under high magnification there is no noticeable difference in the glands at the two seasons.
Rathke has given the name of “Geschmackwärzchen” to the conical projections found on the dorsum of the crocodilian tongue; they are distinguished by their softness and thinner epithelial covering from the cones that, in many of these animals, bear the openings of the mucous glands.
These taste papillæ generally have the form of a truncated cone and often are surrounded by a shallow circular pit, outside of which, in turn, is sometimes a small low wall. They are distributed over the entire dorsum of the tongue, usually at considerable distance from each other in comparison to the size of the tongue, and are not so numerous as the taste papillæ of the Mammalia. Rathke found their absolute number greatest in A. lucius.
Rathke mentions other larger and harder projections on the tongue of certain Crocodilia which, though not perforated by a mucous duct, he thinks are of questionable relation to the sense papillæ. They usually have more the form of a flattened than of a truncated cone, and are very numerous in some species.
The Roof of the Mouth.
In the paper mentioned above the author notes that the papillæ on the roof of the mouth are evenly distributed and are more distinct than those of the dorsum of the tongue. One of these papillæ as seen under fairly high magnification is shown in [Figure 40].
Fig. 40. The covering of the roof of the mouth of the hibernating animal, under fairly high magnification; a, areolar tissue; e, epithelium; h, horny layer; f, fibers of horny layer.
The areolar tissue, a, forming the base of the section is of about the same character as seen in the section of the tongue. Less than one tenth of the thickness of the entire areolar base is shown in this section.
The epithelium, e, where not thrown into papillæ, has also about the same character as that of the anterior region of the tongue—the same number of cell layers and the same distinct horny layer.