1889.] 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 paraffiue 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 'Elements of Compara- 

 tive 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. 



VII. 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 tbe body-wall and the inner peritoneal layer that wraps round 

 the abdominal viscera, appears to be merely an enlarged represen- 

 tative 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 pre- 

 viously 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 



1 As are the fat-bodies in certain snakes and lizards, so this would furnish no 

 argument for regarding it as the spleen. 



