SECTION TWO 



taking precautions to prevent the loss of alcohol by evaporation 

 from the staining solution. 



2. Proceed exactly as at Stage 4 in the technique given for 

 frozen sections, except at Stage 12 the staining time for the cresyl 

 fast violet should be increased to three minutes. 



(d) Celloidin sections (affixed) 



1. Cut sections 15 to 30ja in thickness, keeping the microtome 

 knife and tissue continually flooded with 75% alcohol. 



2. Place sections on slides, which have previously been smeared 

 with glycerine albumen. 



3. If necessary flatten out the sections on the slides by rolling 

 with a piece of glass tubing half an inch in diameter and about two 

 inches in length, or a small glass phial will serve the purpose. 



4. Drop on sufficient clove oil to cover the sections and leave 

 the oil to act for five minutes. 



5. Remove the clove oil with 95% alcohol. 



6. Remove the Celloidin with absolute alcohol. 



7. Wash with 95% alcohol. 



8. Proceed exactly as at Stage 2 in the technique given for 

 frozen sections, except at Stage 12 the staining time for cresyl fast 

 violet should be increased to six minutes. 



Results : 



Myelinated fibres are sharply contrasted greenish-blue against 

 the reddish-coloured Nissl cells. The technique shows the Nissl 

 picture and differentiates between the three types of glia cells: 

 Myelin sheaths, neurons and glia nuclei are well demonstrated. 

 Differentiation is also obtained between the three layers of 

 medium-sized and larger blood cells, and capillary endothelium as 

 well as mesothelial lining of Arachnoid membrane are sharply 

 outlined. The finer fibres of the molecular layer of the cerebral 

 cortex can be most effectively demonstrated in paraffin sections. 

 Bacteria and pigments in nerve cells are more clearly demonstrated 

 with this technique than with the usual Nissl stains. 



Note: In the original paper it is stated that this cell-fibre stain 

 has been employed for peripheral nerves as well as structures of the 

 central nervous system in amphibians, birds and mammals (rat, 



279 



