40 L. S. ROSS 
For neurofibrillae the most satisfactory results were obtained 
by the Cajal procedure used by Boulé (’07) for Lumbricus 
which I have modified only by using formol neutralized with 
magnesium carbonate instead of adding ammonia to the commer- 
cial solution. The method employed by Cowdry (712), which 
involves fixation in the 6:3:1 mixture of Carnoy followed by 
silver impregnation and reduction with pyrogallol, and the 
Ranson pyridine-silver method were used also. 
For the internal reticular apparatus of Golgi the original 
Golgi technic and the Kopsch and Cajal methods were tried, 
but nothing was obtained in the large ganglion cells which could 
be interpreted positively as this apparatus. 
3. General histological methods 
In some respects the most striking results were obtained by 
the use of Bensley’s (’11) ‘A. O. B.’ method. The mitochondria 
are preserved and stained, the Nissl substance can be dis- 
tinguished, and the intracellular axone is sharply differentiated 
with the individual fibrillae distinct. The procedure is as 
follows: 
1. Fix 2 to 4 hours in: 
Potassium bichromate, 2.5 per cent, 16 cc. 
Osmic acid, 2 per cent, 4 ce. 
Acetic acid, two small drops. 
. Distilled water, few minutes. 
. Grades of alcohol to absolute, 2 to 4 hours each. 
. Aleohol 100 per cent and bergamot oil, half and half, 1 hour. 
. Bergamot oil, 1 to 2 hours. 
. Bergamot oil and paraffin, half and half, 1 hour. 
. Paraffin, 60°C., 2 hours. Section 41; fix to slides. 
. Remove paraffin with toluol or xylol. 
. Aleohol 100 per cent down through grades to distilled water. 
. Potassium permanganate 1 per cent, 15 to 30 seconds. 
. Oxalic acid 5 per cent, 15 to 30 seconds. 
. Stain 4 to 5 minutes at 60°C. in Altmann’s anilin fuchsin: 
Anilin water, 100 ce. 
Acid fuchsin, 20 grams. 
13. Rinse in distilled water. 
14. Methyl green or toluidin blue 1 per cent solution or Wright’s blood 
stain, a few seconds to be determined by trial. 
15. Drain, dehydrate in alcohol 100 per cent, usual procedure for mounting. 
For tissue masses larger than crayfish ganglia it may be necessary to extend 
the time in the process through no. 7. 
See 
Nr COON ®D OP | LO 
