454 



ELEMENTARY ANATOMY, 



[LESS. 



it is almost always very much more simple. Thus, in Fishes 

 the liver consists generally of one undivided mass, or of two 

 lobes, as in the Cod ; or three, as in the Carp and Rays very 

 rarely of more, as in the Tunny. 



In Reptiles the liver is single, as in the Chameleon and 

 Serpents, or consists of two lobes, as in the Crocodile. 



In Birds there are also two lobes, to which sometimes (as 

 e.<r. in the Swan) there is added a small intermediate lobe 

 at the back, which has been deemed to answer to man's Spi- 

 gelian lobe. 



It is in man's own class, however, that the varieties 

 greatest both in number and interest present themselves. 



FIG. 385. IDEAL DIAGRAM OF UNDER SURFACE OF LIVER, the front margin 

 being turned upwards. 



(After Flower.) 



c caudate lobe cf cystic notch ; dv, remnant of ductus venosus ; g, gall-bladder ; 

 Ic left central lobs ; //, left lateral lobe ; llf, left lateral fissure ; p, portal 

 fissure ; re, right central lobe ; rl, right lateral lobe ; rlf, right lateral nssure ; 

 s, Spigelian loba ; it, remnant of umbilical vein ; vc t vena cava. 1 he arrow 

 points to the vena cava. 



The study of them has led to the perception that the most 

 definite and typical structure of the liver is as follows : (i), A 

 Spigelian and (2) caudate lobe, each defined as in man ; 

 (3 and 4), two divisions of that part of the liver which lies on 

 the left side of the broad ligament, and which are named 

 respectively the "lateral left lobe" and the "central left 

 lobe;" (5), the lobe which supports the gall-bladder, and 

 which is called the cystic, or " central right lobe ; " (6), the 

 extreme right part of the great right lobe, often separated 

 from the central right lobe by a fissure, and named the 

 *' lateral right lobe," 



