STRUCTURE OF THE LOBULES OF THE LIVER. 9 



and sometimes so arranged as to present transitional forms to 

 all of the above. 



For ths due investigation of the internal structure of the 

 lobules, it is requisite to obtain very thin sections that shall 

 not materially exceed the longest diameter of an hepatic 

 cell, whilst the capillaries should be moderately distended 

 either with blood or by means of an injection, the tint of 

 which has not been made too deep. Considerable attention 

 should also be paid to the process by which the hardening of 

 the organ is effected. In alcohol, as well as in chromic acid, 

 the hepatic cells become shrivelled, and then separate more or 

 less completely from the neighbouring capillaries, so that a 

 space is formed between the cells and the capillaries. The 

 cells fall out of the capillary plexuses, and separate from one 

 another very easily in preparations that have been hardened 

 in chromic acid. These phenomena are by no means exclu- 

 sively dependent on the concentration of the hardening fluid, 

 nor upon the duration of its action, but rather on the condi- 

 tion of the liver, which, of course, varies to a very considerable 

 extent, according to the nature of the antecedent disease, and 

 the time after death at which the organ was first obtained and 

 subjected to the action of the hardening fluid. In the livers 

 of certain animals, as for example of the Rabbit, these evils 

 are not to be feared, since not only can the organ be obtained 

 in the perfectly fresh state, but the cells do not here easily 

 become detached from the capillaries. The structure of the 

 liver in the Rabbit, however, is somewhat different from the 

 account that has been given above, the number of the capil- 

 laries in proportion to the hepatic cells being rather greater, 

 so that each cell is in contact with three or four radial capil- 

 laries. The appearances presented by the liver in this animal, 

 which I have elsewhere* more fully described, cannot therefore, 

 without some restrictions, be considered as applicable to Man. 

 The structure of the liver of the Dog is much more analogous 

 to that of Man. 



The above account of the structure of the hepatic lobules differs 



* Sitzungsberichte der Wiener Akademie der Wissenschaften, vom. 6th 

 Dec., 1866. 



