TERMINATION OP NERVES IN THE LIVER. 443 



are found running around the capillaries between these and the 

 hepatic cells. They touch, pass between, but do not enter the 

 latter as Pfliiger maintains. Holbrook asserts that the fibrils 

 are connected with the cement substance or protoplasmic bridges 

 between the cells, and thereby with the outer portion of the cell 

 reticulum. He also corroborates the results of Nesterowsky's 

 researches. 



Methods. 



To demonstrate nerve-structures in the liver of Necturus 

 the method employed was as follows : Pieces of the liver were 

 hardened for a week or more in Erlicki's fluid, or for several 

 days in a ^ — -^ per cent, solution of chromic acid. After the 

 hardening was sufficiently completed in alcohol, sections of the 

 frozen tissue were made with a Cathcart microtome. These, 

 when the gum was carefully removed, were put in a weak solu- 

 tion of formic acid (5 per cent.) for an hour, transferred to a 

 1 per cent, solution of gold chloride for about twenty minutes, 

 then washed in distilled water, and the gold afterwards reduced 

 in the dark with a 10 per cent, solution of formic acid. About 

 thirty hours sufficed for this reduction when the temperature of 

 the room was 20° C. The sections then had a deep red colour, 

 but sometimes the tinge was violet. The chromatine of the 

 nuclei of the hepatic cells took a deep blue violet tint, the 

 caryoplasma light violet, while the cytoplasma came out very 

 distinct as a meshwork with a pink or light carmine colour. 

 The nerve-fibres appeared deep violet, but the connective tissue 

 of the interlobular spaces attained a light red, sometimes a 

 deep red colour. 



"When chromic acid was used as a hardening reagent the 

 addition of any organic acid at the same time, such as acetic 

 acid more especially, seemed to me to have the effect of robbing 

 the nerve-fibres of their selective capacity for gold, while it 

 increased the eff"ect of the latter on the remaining constituents 

 of the liver. 



I do not know whether chromic acid or Erlicki's fluid ofi'ers 

 in the method described more advantages. If there is any 

 advantage at all it is to be obtained from the former reagent. 



