1889.] FAT-BODIES OF THE SAUROPSIDA. 603 



Page 



V. On certain Subcutaneous Fat-deposits 609 



VI. On the ftitty" Spleen "of the Crocodiles 610 



VII. Conclusions 611 



VIII. Explanation of the Plates 612 



I. Introductory. 



The conditions under which the investigations of which this paper 

 gives the results were commenced and carried on were stated in the 

 introduction to my paper upon the Subdivision of the Body-cavity, 

 read at the last meeting (see above, p. 452). 



II. On the Relations of the Fat-bodies of the Sauropsida, 



AND ON certain PoINTS IN THE AnATOMY OF MONITORS. 



The fat-bodies referred to are those which, as is well known, 

 occur in Lizards on the course of the "pelvic" veins, and of more 

 or less of the anterior-abdominal vein. The vessels named, with 

 their tributaries, take away the blood, which is brought to the fat- 

 bodies by large branches from the anterior of the two pairs of 

 arteries that supply the hind limbs, and which I take to be homo- 

 logous with the femoral arteries of birds. 



Corresponding fat-bodies are very conspicuous in the Snakes {cf. 

 figs. 8, 9, & 10 c.a), where, as in the Snake-like Amphisbaenidse, 

 they extend from the cloaca to the hinder margin of the liver {cf. 

 figs. 4, 5, 6, 7). The figures of sections of Adder and embryo Grass- 

 Snake show that, when the fat is well developed, the peritoneal 

 cavity of Snakes may be much restricted by reason of the fact that 

 the kidneys and fat- bodies lie outside it. The latter occur in the 

 Crocodiles, but, as described below, the fat-bodies here referred to 

 are in these animals more lateral in position than in Lizards ; and in 

 the case of the birds, the fat-laden " omentum," or transversely 

 expanded ventral ligament of the stomach, is, I think, obviously 

 comparable, so far as its fat is concerned, to the similar fat-laden 

 ventral ligament in such forms as the Amphisbseuidae and Snakes, 

 where the fat extends forwards as far as the liver. 



The Chelonia are the only order of the Sauropsida in which I 

 have not observed these structures well developed, but there appear 

 to be traces of them in Emys europcea ^ 



In many Lizards {cf. fig. 1 1) these fat-bodies, pushing the 

 peritoneum before them, bulge into the body-cavity ; and, lying on 

 the course of the large vessels ventral to the (once respiratory 

 allantoic) bladder {cf. figs. 7 & 12) and the alimentary canal, into 

 the ventral ligament of which they in some forms (Amphisbsenidae, 

 fig. 4) obviously extend, they may form paired masses quite as con- 

 spicuous in the posterior part of the abdominal cavity as are the 

 liver-lobes in the anterior half ^. 



1 I have onl}' examined in this connection some half-dozen specimens of 

 Emys and Testudo, and those not large ones. 



^ These lie, of course, ventral to the alimentary canal and lungs. Passing 

 over the important difference that no branching system of tubules extends from 



40* 



