478 ANATOMY OF VERTEBRATES. 



if a simple condition of stomach is retained, it must be compen- 

 sated by a large sacculated colon and cascum. 



§ 338. Liver of Mammalia. — The liver, as a rule, is divided 

 into a greater number of lobes in the present than in the pre- 

 ceding classes, the body being more flexuous at the seat of the 

 viscus. In the stiff-trunked Whales and erectly-moving Man the 

 organ is more compact : and it is least subdivided in the purely 

 herbivorous Ungulates where a minor degree of hydrocarbonates 

 has to be eliminated. Thus, in a full-sized Giraffe, the liver 

 weighed but 6 lbs. lloz. avoirdupois ; it was of a flattened, wedge- 

 like form, consisting of one lobe, with a small posterior Spigelian 

 process; its greatest breadth was 12 inches; its dorso-ventral 

 diameter, 8 inches. The postcaval vein passed through a notch 

 at the posterior edge of the liver, and did not perforate it. In 

 all Ruminants the liver is confined to the right hypochondriac 

 and epigastric regions. In most, two lateral lobes are indicated 

 by a small fissure at the entry of the suspensory ligament. In 

 the Ox, the main part to the right is partially subdivided into 

 two, with the l Spigelian ' process from the back part of the right 

 subdivision : with a breadth of 13 inches and a dorso-ventral 

 diameter of 10 inches, the greatest thickness does not exceed 

 3 inches. In the Camelida the under surface of the liver is sub- 

 divided into many polygonal lobules of small but varying size : 

 the fissures between some of which extend to the convex surface. 



In Cetacea the liver more resembles that of the human 

 subject, but is not so thick at its base nor so sharp at the front 

 or ventral edge. The right lobe, e, fig. 355, is the largest and 

 thickest; the falciform ligament is broad, and there is a deep 

 fissure, g, between the two lobes, into which the round ligament 

 passes. The left lobe, f, is extensively and firmly attached to 

 the stomach, the small omentum being a thick substance. 



In Sirenia the liver is flatter and more transversely extended. 

 In the Dugong the liver is a transversely oblong viscus, divided 

 into three lobes with a fourth small process at the root of the left 

 lobe, representing the lobulus Spigelii. It is as usual convex 

 toward the diaphragm, but rather flattened than concave toward 

 the viscera, the anterior margin is thick and rounded. Of the 

 three larger lobes the middle one is the smallest, of a square 

 shape, projecting forward, and as it were over-hanging the gall- 

 bladder, which is lodged in the middle of the inferior surface. 

 The ligamentum suspensorium is continued upon the middle lobe, 

 immediately above the gall-bladder, the anterior margin of this 

 lobe being notched to receive it, and the remains of the umbilical 



