The finer Anatomy of tbe Nervons System of Myxine glutinosa. 367 



The GoLGi treated braius were directly transferred to Alcohol 

 Absolutus, ether-alcohol, thick celloidin, and as soon as possible 

 hardened in chloroform, cleared and cut in the way recommended 

 by Fish. His method is excellent for Golgi preparations which 

 may be mounted directly and which do not require any after treat- 

 ment. 



In cutting the brains in their capsules, care must be taken to 

 paint each section with a photoxylin solution before it is cut, as 

 otherwise the brain substance will generally get torn from the rest 

 and defective sections result. Celloidin imbedding will also be 

 necessary when the brain is cut in its capsule, as the cartilage 

 contained in the latter is too hard to be cut in jiaraffm, but in the 

 case of brains wiiich have been removed from their surroundings, 

 paraffin imbedding was used in all cases except with Golgi pre- 

 parations. 



The method of Weigert is of course of no avail in Myxine, 

 as this animal has no meduUated nerve-fibres, but the Iron-haema- 

 toxylin method of Heideniiain, in the way used in this investigation 

 and hereafter described, has given me excellent results. 



The object was hardened in Kultschitzky's fluid and trans- 

 ferred without washing into Alcohol of 90^, from that to Alcohol 

 Absolutus, imbedded in paraffin in the usual way, cut, and the 

 sections mounted on the slides with Aqu. Dist. After the removal 

 of the paraffin the sections remained in the Iron-Alum solution for 

 11/2 hours, were then washed in repeated washes of A(iu. Dist. and 

 transferred to the Haematoxylin solution for 24 hours. The diflereu- 

 tiation takes place in the usual way, but care must be taken not 

 to let it proceed too far. 



If the staining has succeeded perfectly, the large nerve-cells 

 and their processes are stained black or dark gray, the entering 

 motor nerves define themselves from the surrounding tissue and, 

 where the sections are cut on a suitable level, are easily followed 

 to the ganglion cells from which they issue. 



The commissures of the brain and spinal cord are distinctly 

 shown by the same method and the sensory nerves, even if not so 

 distinctly stained as the motor ones, may be followed for relatively 

 long distances. 



As regards the commissures of the brain, still more distinct 

 results were obtained in some cases by the Walters haematoxylin 

 method. 



