TERMINATION OF NERVES IN THE LIVER. 447 



liver be treated with gold chloride, and the process of colouration 

 be watched, it will be found that the first tinge which the 

 nerve-fibres take is red, and afterwards they show all stages 

 transitional between that colour and violet, while the other 

 systems of tissue slowly pass through the same order of colours 

 to the violet tint. The nuclear chromatine is an exception, 

 being, like nerve-tissue, quick to attain a violet tint. Occa- 

 sionally other structures act like nerve-fibres towards gold, and 

 among these may be mentioned certain paranuclear bodies in 

 the cutaneous epithelium of Nectur us which are first coloured 

 red, then rose violet, and finally deep violet. This appears to 

 show that the substance which fixes the gold in a violet form 

 is not confined to nerves, but is diffused to a small degree in 

 other tissue elements. 



The finest nerve-fibrils being hardly thicker or less delicate 

 than the trabeculse of the cytoplasm a, it is wrong to suppose 

 that a reagent which does not specially preserve and fix the 

 latter will do this for the former. It is in this respect that I 

 find the reason for the failure of Nesterowsky, Kolatschewsky, 

 and others to resolve the finer nerve terminations, seeing that 

 the reagents they used for hardening the tissue do not render 

 the cytoplasma distinct and firm, and with it the finer nerve- 

 fibrils. Ammonium bichromate is not a suitable reagent for 

 this purpose, neither is the weak solution of chromic acid such 

 as Kupffer used. The same objection can be urged against the 

 method of freezing the fresh liver in order to obtain sections. 

 The method of gold colouration must not be allowed to injure 

 the cytoplasma. The test which I always exacted of the 

 method employed was the distinct demonstration of the cell 

 reticulum; that being in a good state of preservation, it was 

 only a question of the number of trials with gold chloride in 

 order to get the desired demonstration of the termination of 

 the finest fibrils. I think also that the clearing up of fresh 

 tissue with formic or acetic acid previous to steeping in gold 

 chloride is apt to destroy both the cytoplasma and the finest 

 nerve-fibrils. It is on this ground that I advocate the use of 

 chromic acid to fix these before subjecting them to the action 



