THE LIVER. 135 



[The investigation of the liver is best undertaken in the Pig, 

 in which animal the distinct demarcation of the lobules greatly 

 facilitates the comprehension of the relations of the secreting 

 parenchyma, to the vessels and hepatic ducts. The hepatic 

 cells may be isolated with the greatest ease in all animals, 

 either singly, in series, or in reticulated fragments ; but to com- 

 prehend rightly their collective arrangement no better means 

 exist than the making of fine sections in a fresh liver with 

 the double knife, for which, sections made off-hand with a 

 razor, even in a liver previously hardened in alcohol, pyro- 

 ligneous acid, chromic acid, &c, are by no means suffi- 

 cient substitutes. We do not mean to say that the hepatic- 

 cell network cannot be seen at all in this manner, for it is 

 visible even in opaque sections of liver by reflected light, but 

 merely that no complete view can thus be obtained. The finest 

 hepatic ducts are not readily found, though a careful search in 

 nearly all sections which include many lobules, will almost cer- 

 tainly detect scattered fragments of them, readily recognisable 

 by their small polygonal cells, at the edges of the lobules, and 

 long examination may perhaps eventually discover such a frag- 

 ment in connexion with the hepatic-cell-network, which, how- 

 ever, I have not yet succeeded in doing. The coarser biliary 

 ducts present no difficulties. Their glands are seen readily, 

 partly with the naked eye, partly by the use of dilute caustic 

 soda. Weber's anastomoses of the two hepatic ducts in the 

 fossa transversa, are visible in good injections. The vasa aber- 

 rantia, in the left triangular ligament and in other localities, 

 are readily perceived even without injection, on the addition of 

 acetic acid or of caustic soda. The nerves and lymphatics of the 

 liver are, except their finest portions, easily seen in Man. The 

 blood-vessels require good injections, for which purpose, in the 

 human subject, I especially recommend children's livers, in 

 which the distribution of the arteria hepatica in the serous 

 coat, on the vessels, &c, is beautifully distinct. The capillary 

 network of the lobes may readily be filled with fine injection, 

 and a series of excellent preparations of this kind, by various 

 masters of the art, are everywhere to be met with.] 



of the intestine — the future ductus choledochus ; and that, in the course of develop- 

 ment, the diverticulum grows into and ramifies in the mass — its ultimate branches 

 terminating in caeca. The gall bladder is not formed till very late. — Eds.] 



