The variety of appearance in the vascularity of the lobules in congestion, and the constancy of its occurrence, have deceived those patholo gists who maintain the existence of two sub stances, and the difference of position and form of the congested and uncongested portions has given cause for the diversity of opinion with regard to its situation. For a perfect elucida tion of these difficulties, physiology is indebted to the genius and perseverance of Kiernan. The mode in which the attention of this author was drawn to the subject forms part of the his tory of hepatic congestion, and deserves to be detailed in his own words. "My attention," he observes, " was first directed to the anatomy of the liver by the study of the ad mimble works of M. Andral. In the first organs I examined I found the small branches of the hepatic veins ramifying exclusively in the red,1 and those of the portal vein in the yellow substance. I concluded that the liver was composed of two venous trees, a portal and an hepatic tree, the former having a cortex of yellow, the latter of red substance ;and with M. Bouillaud, I thought it probable that the red substance was the organ of the function imagined by Bichat. I next ascertained the lobular structure, and concluded with Ferrein, that the red substance was me dullary and the yellow cortical. Subsequent dissections, in which I found branches of both the portal and hepatic veins ramifying in the red substance, tended to unsettle the opinions I had formed respecting the anatomy and physio logy of the two substances, and these opinions were finally overturned by the examination of a liver in which I found the branches of the portal vein alone ramifying in the red, and those of the hepatic veins in the yellow sub stance. The only conclusion t1TAI could be drawn was, that the red colour resulted from congestion ; that it was medullary, occupying the centre of each lobule, when the hepatic, and cortical forming the circumference, when the portal vein was congested." Muller, in the eleventh figure of plate 11 of his admirable work on the glands, has made a singular error with regard to the structure of the liver, and the arrangement of the ultimate biliary ducts. In the description of this figure he says, " Segmentum hepatis Sciuri junioris, rnicroscopio simplici visum. Observantur fines ductuum biliferorum elongati, seu cylindri formes acini, in figuris ramosis ct foliatis vane dispositis." Now the truth is, that this section is in the second stage of hepatic venous con gestion, and the "figuris ramosis et foliatis" are simply the uncongested portions of the lobules, of a lighter colour than the rest, and presenting the foliated and ramous appearance which is common to this form of congestion. The "fines ductuum biliferorum elongati seu cylindriformes acini" are obviously imaginary. The dark lines in the centre of the foliated ra mifications are small branches of the portal vein lodged in interlobular fissures. If the twigs given off by these branches be made to unite with each other, we shall then have the true form of the lobules. This has been done in fig. 45, upon a part of Miller's drawing, for the purpose of skewing how the error has arisen, and how the form of the lobules may be restored. This appearance of the congested liver is by no means unfrequent in occurrence, and I subjoin a careful and accurate drawing of a similar arrangement in the human liver, (fig. 46,) for the purpose of comparison with that of Miller.
Coming from so high an authority as Muller, this figure has been copied without hesitation by several writers, together with the explanation given of it by the author. Mr. Grainger has introduced it into his article upon the glands in this Cyclopmdia,fig. 217, page 485, and Mr. Carpenter has also given it a place in his recent excellent work • on physiology. In his text, the latter gentleman observes with regard to the figure :—" In the squirrel indeed these pro longations may be distinctly seen, the blind sacs being cylindrical in form, and closely packed together."
Hepatic venous congestion in its most com mon form, viz., in the second stage, is the great stumbling-block of all anatomists who have engaged in the investigation of the minute anatomy of the liver; and it is under this head that I must now consider the views of Cruveilhier with regard to the supposed nor mal anatomy of this organ. Isolated from the distribution of the vessels in the liver, he has described the form and arrangement of the lobules with sufficient accuracy ; but then it must be remembered that his description was written subsequently to the publication of the researches of Kiernan. But his conception of the structure of the lobules is completely erro neous, for after combating the common error of the existence of two distinct substances, lie says :—" Les deux couleurs jaune et brune quand elks existent, n'appartient pas a deux granulations distinctes, mais bien a Is tame granulation qui est jaune au centre, oil se tronve le bile, et ronge-brun a la circonference, oh se trouve le sang." Now Kiernan has dis tinctly proved that the structure of the lobules is the same throughout, and their colour is also uniform. Cruveilhier must therefore have founded his opinion and his description upon a liver in the second stage of hepatic conges tion, in which there exists a delusive indication of lobules having the appearance of small oval and variously shaped patches, of a yellowish colour, situated at regular intervals, and sur rounded by a reddish brown substance. These yellowish spots are seen in figs. 43, 45 & 46. They are the clusters.of terminal biliary ducts of Miller,—the central portions of the lobules of the liver of Cruveilhier; hut if they be ex amined carefully, their true nature will become clearly apparent. They are actually the un congested portions of the lobules of a liver in the state of hepatic venous congestion at the second stage, and have each an interlobular space for a centre. In the next passage Cru veilhier observes :—" Le foie humain, excepte dans les cas de divelopment considirablc des granulations, se prete difficilement it leur etude vu leur petitesse." Ilere again in the words "development considerable," we perceive an idea founded upon the same erroneous im pression with regard to the structure of the lobules. The real lobules are as nearly as pos sible of the same size in the liver of every individual, but these imaginary lobules of Cruveilliier, having uncongested portions of the hepatic substance for centres, necessarily vary in size and form with the degree of con gestion, and hence have given rise to the idea of an increased development of the lobules. Again, the true lobules are not so small in the human liver as to render their examination difficult ; they may be seen distinctly with the naked eye, and with the commonest lens may be examined accurately. But in the congested state of the organ they are more obscure, as may easily be inferred when we perceive such distinguished authorities as Muller and Cru veilhier, from want of making the liver the subject of especial investigation, deceived by such appearances. That Cruveilhier has actu ally mistaken the uncongested patches seen on the surface of a congested liver for the lobules, is clearly proved by a succeeding paragraph :— " Du reste, le volume des grains glanduleux presente beaucoup de varietes suivant les indi vidus, et ce volume est tout-a-fait independant du volume du foie lui-meme. Les medecins qui d'anatoinie pathologique ont sou vent note ce development, sous le titre d'hepar acinosum. II est une maladie caracterisee par la coincidence de l'atrophie du foie, qui est reduit a la moietie, au tiers de son volume, et du development considerable des grains glan duleux." Now the hepar acinosum is without question a liver in the second stage of hepatic venous congestion, and presents several varie ties in the precise form of the uncongested patches.