whole alimentary tract is thrown into a series of very deep folds, which appear to be a continuation of the longtitudinal mucous folds of the œsophagus; they wind to and fro in such a manner, bending backwards and forwards, and interlacing with each other, as strongly to resemble the appearance presented by the gizzard of a fowl (see Fig. 4, Pl. II.); and when acting under the control of the muscular coats of the stomach, must form a very effective triturating apparatus. Four or five of these folds enter into the intestine, and here, for about a quarter of an inch, they become but very slightly elevated; as they approach that peculiar semiflexion in the intestine referred to above, they increase in number, and also in depth (Fig. 4), and, from their very close and compact appearance, I am led to suspect that this portion of the intestine, between the pyloric orifice of the true stomach and the orifice of the biliary ducts, is more than an ordinary duodenum, and acts somewhat as a secondary stomachal cavity. This idea is strengthened by the additional fact, that the true stomach is lined with a series of minute pores, thickly scattered over the mucous surface, and covering both the raised folds of the mucous membrane and the intestines between them. These small pit-like indentations are minute glandular bodies, secreting the gastric juice; they commence just below the cardiac orifice of the stomach, and are continuous to the entrance of the biliary ducts. While every part of this portion of the intestine is supplied with these crypts, of course they are most numerous when the mucous membrane is thrown into a series of folds; this occurs in the secondary stomachal portion alluded to, which, in every anatomical particular, is a miniature of the larger one.
The mucous surface of the small intestine becomes much smoother after it has received the contents of the liver. But in no one spot throughout its length do we find it absolutely smooth; it is always arranged, more or less, in a series of delicate, longitudinal folds; and, as we approach the rectal portion, these folds assume a slightly twisted appearance, but not at all distinct enough to be alluded to as a spiral valve. When the small intestine joins the large rectal cavity, the gut, as above-said, contracts very much, and the mucous membrane is packed up into two or three little eminences, which act the part of a valve. In the rectal portion, the lining membrane is thin, and very smooth. In this, as well as in its large diameter, in comparison with the small intestine, it remarkably resembles the same parts in the Tritons and Salamanders.
From a survey of the details thus glanced at, it will be seen that there is nothing in the alimentary canal of the axolotl to predicate of it that it is a larval form; though it may resemble the same parts in an adult Salamander and Triton, yet it differs from these more than was at first thought, and more than one would imagine from the only account that I have found attainable, namely, that of Baron Cuvier. The osseous system has been too well described by Cuvier, and the reproductive by the paper and illustrations of Sir Everard Home, to need further allusion to at my hand.
