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Show 1°89.] FAT-BODIES OF THE SAUROPSIDA. 611 analogous to the pancreas aselli, viz. a lymphatic gland ; it is a good deal like the spleen of a bird." In a paraffine section of a spirit-specimen this latter seemed more like a spleen than that first mentioned, which resembled rather a " fat-body " with an unusual supply of blood-vessels. I have no desire, however, to venture an opinion on histological grounds, especially as the preparations were not very good. In young specimens, within the egg, this body is as distinct as in the adult \ but it is quite yellow and soft, and fatty. I have not seen any body corresponding to this in any other reptile, except in one out of two specimens of the lizard Lialis, in which there was a long yellow body with a very similar attachment (behind the end of the right liver-lobe), only more elongated than in the Crocodile. This, however, one would expect, considering the snake-like attenuation of the body in Lialis. This body occurred in a male. The other specimen that I saw was a female and contained no trace of such a body, thus differing from the Crocodiles, where both sexes possess the fatty "spleen." In Parker's translation of Wiedersheim's '6Elements of Comparative Anatomy of Vertebrata' it is suggested that the "fat-bodies" of Reptiles should possibly be placed in the category of lymphoid tissues; and this suggestion may perhaps indicate a solution of the question as to this fatty " spleen " of Crocodiles,-may explain, 1 mean, the existence of a body at once resembling a normal lymphoid spleen and a lymphoid (?) " fat-body." On the other hand, the situation of this structure is, but for the fact that it occurs only on the right side, largely suggestive of the corpus adiposum of the Amphibia. VIL CONCLUSIONS. (1) Deposits of fat, subperitoneal and subcutaneous, appear, among the Amniota, to have just such a constancy of distribution as one would expect of such deposits situated on the course of leading blood-vessels. (2) The relations of the subperitoneal fat-bodies in the various groups of the Sauropsida correspond, and these bodies seem to admit of comparison with the subperitoneal fat of mammals. (3) In the Monitors the space between the main, parietal, portion of the body-wall and the inner peritoneal layer that wraps round the abdominal viscera, appears to be merely an enlarged representative of the spaces round the fat-bodies in other lizards. (4) The question of the relation of the Monitor's lungs to the body-cavity, from the abdominal portion of which they are, as previously described (Martin, Beddard), excluded by a "membranous diaphragm," needs further investigation. Such a condition seems not to be realized in any other reptiles except the Chelonia (Testudo). (5) So far as the subdivision of the body-cavity is concerned, the i As are the fat-bodies in certain snakes and lizards, so this would argument for regarding it as the spleen. |