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the intedines, and the apex of the heart is accommodated m 

 the middle, and wherever the hver comes into cor.taa with 

 thcfe parts, it receives in a degree an imprefllon of their form. 

 Vic d'Azir, in his great fyftcm of anatomy, fays, that 

 the Hver of birds is divided into only two lobes ; and Cuvier 

 has repeated the afl'crtion in his Tableau Elementaire de 

 I'Hilloire Naturtlle. The obftr\'ation, nevtrthclefs, is not 

 in all cafes ftriaiy true. In many birds there is a third lobe, 

 fituatcd at the back of the liver, between the right and left 

 lobes : this appears to be analogous to the lobuhis fpigelii of 

 the human fubjed, both from its moft ufual figure, and from 

 itspofition. Ste r/alelV.of ihe /inalomy o/Birds. Fi^-S- 

 reprefents the liver, &c. of the goofe reviewed on the pofterior 

 or reverfe fide ; a the right lobe reaching lower down than the 

 other, and exhibiting impreflionscorrelponding to the convo- 

 lutions of the inteftines; 6 the left lobe, with two prominent 

 parts,andadcprc(Iion extending alonglhe lobebetwcei; them; 

 c the third, or intermediate lobe. In the common fo-wl, the 

 left lobe is cleft on the anterior part fo deeply as almoll 

 to form two lobes on the left fide. The French academi- 

 cians allow three lobes to the liver of the cormorant; they 

 are all very fmali. A third lobe has been defcribtd alfo 

 in the pigeon by Borrichius, and in the /-Man by Bar- 

 tholine. The liver of the o/lric/j conlifts of four imperfecl 

 lobes. 



There is confiderable variety in the (hape and relative fize 

 of the two principal lobes ; generally the right lobe much 

 exceeds the other in bulk, and is fomewhat longer. This 

 charafter of the lobes is to be fccn in the liver of the goof; 

 Plate IV. ^g. 5. but is more remarkable in the ca^tiwary, 

 and even llill more fo in the hujlarj, in which the right 

 lobe defcends to the bottom of the belly ; both lobes are 

 ftiort in the eagle, the Indian cock, the parrot, the otvl, and 

 many others ; and in the eagle the left lobe has the greater 

 bulk. 



The two lobes are nearly of equal fize in the heron kind, 

 and both long (haped. However much the livtrs of birds 

 may differ in external forms, the internal ftrnClure is the 

 fame in all cafes, as we have proved by numerous obferva- 

 tions. The fecretory veffel is produced from the veins of 

 the neighbouring vifcera, as in mammalia, and after enter- 

 ing the liver by the dcprelfion or fifTurt on the lower furface, 

 which correfponds to thenar/,* or gates of the human liver, it 

 isdiftributed throughout the fubftance of the organ, and ter- 

 minates in the fame manner as the ■zn-zxr /o/V/f, i.e. in fine 

 radii, rr penicilli towards the furface of the liver. 



As there is no mufcular feptum between the thorax and 

 abdomen of birds, tlieir liver has not the advantage of that 

 mode of conueclion, which is called in mammalia the coronary 

 ligament : it is however amply fupplied by the duplicature of 

 peritoneum, whic'i correfponds to the falciform ligament ; 

 this procefs divides the two principal lobes, paffing deeply 

 between them ; it is connected to the peritoneum., which 

 forms the air cells, in the fides and back part of the abdomen, 

 is incorporated with the pericardium, and joins the fternum 

 and the linea alba on the fore part of the abdomen, and then 

 becomes reflected on each fide of the common cavity, which 

 is thus divided almoft for its whole extent, in the fame man- 

 ner as the mediatlinum divides the thorax in mammalia. The 

 extended attachment, which is in this way procured for the 

 liver, renders this vifcus more fteady in its fituation than it is 

 in other animals, which birds require on account of the rapid 

 and violent motions of their bodies during the adl of flying. 

 As the falciform ligament goes on to the fore part of the 

 cavity, the margin which forms the round ligament is ne- 

 celTarily wanting, but the remains of the umbilical vein 



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may be traced running between the duplicature of the perito- 



neum. 



The gall-bag, or refervoir of the fecretcd fluid of the liver, 

 in almoll every inftance where it exiles, is fituated upon the 

 lower furface of the right lobe, fomewhat nearer its central 

 than its external edge. It is commonly received into a flight 

 depreffion of the liver, fo that about one half of the bag ii 

 brouglit into contait with that vifcus, nothing being inter- 

 pofed between them but the connefting cellular fubftance. 

 The furface of attachinent is occafionally Lis extenfive ; thus 

 in the eagle, lujlard, and cormorant, the bag (lands out from 

 the liver being only united to it by one end. 



The foi-m of this bag is commonly that of an egg, or a 

 globe, or often foniething between thefe two figures. In a 

 few inftances it is elongated, as in the bujlard and cajfotuary ; 

 it meafured in the latter bird only one inch in diameter, al- 

 though it is feven inches in length. 



The ftrutlure of the gall-bag appears to differ in no refpeft 

 from that dcfcribcd in mammalia ; its coats difcover no trace 

 of mufcular fibres, and its internal furface exhibits the fame 

 kind of reticulation or net-v.'ork which is found in the gall- 

 bladder of the human fubjeft. See Plate IV. and^^. 5 in 

 the Aitatbmy of Birds ; the letter </ indicates the gall-bag of 

 the goofi viewed particularly in its natural pofition ; the reti- 

 culated {Iruclurc is vifible on the outfide, but to bring it more 

 perfecftly into view the cavity is expofed by the removal of a 

 portion of the bag. 



The bile does rot flow into the gall-bag by regurgitation 

 from the common dudl, but is conveyed direclly thither by 

 means of a particular tube dcfigncd for tliat purpofe. This 

 duct arifes from the right lobe,- pafTes on the fidt of the bag 

 which is in contaft with the liver, then becomes involved in 

 the coats of the cyfl, which it perforates about the dillance 

 of one-third from the pofterior end. 



The orifice by which the duel opens into the cavity of the 

 bag, is very fmall, and is furrounded by a fmooth projection 

 of the inner membrane, which added to the obliquity of the 

 duft, affords the effeCl of a valve, and entirely prevents any 

 return ot the fluid upon the hver ; for the more the cyll 

 is diftended, the more preffure will be laid upon the du<S, in 

 its paffage. 



It wotJd feem that the cyfto-hepatic duft is fituated nearly 

 in the fame way in all birds, where it exifts, but the prefent 

 defcriptio'n is taken from l\\t goofi. See Plate IV. ?.nAJig. 5. 

 in which e points out the termination of the duft in the gall- 

 bag, upon the papilla above-mentioned, and the courfe of the 

 duel alfo is to be indiftindlly feen behind the tunics of thecyft. 

 The duels which carry the bile to the inteftines, are two in 

 number, the hepatic and the cyjlic. The firll arifes by two 

 branches, generally from the right and left lobes of the liver, 

 and while within the fifl^ure or poi ta; of the liver, they unite to 

 form the trunk which proceeds to its infertion in the inteftine, 

 and ufually crofles the dudl of the gall-bag in its way 

 thither. 



The cyjlic du3 comes forth abruptly from the mod pofterior 

 part of the gall-bag, which is not prolonged into a neck, as 

 in other animals. The duft makes a turn round the end of 

 the bag, along the fide of which it then proceeds fo clofely 

 applied, that upon a flight examination it might be fuppofed 

 to commence from that part, or even from the anterior end 

 of the cyft. 



The cyllic and hepatic dufts never unite to form the 

 duftus communis, as in many animals ; but proceed di- 

 ftiriftly to the inteftine, into which they always enter fepa- 

 rately ; fometimes very near each other, and at others re- 

 moved to a little diftance. Two hepatic dufts have been 

 8 found 



