226 BOTANICAL GAZETTE [OCTOBER 
The proportions were as follows: Chromic acid, 0.8”; acetic 
acid, 0.5°; water, 99.0%. The combinations of stains giving 
the best results were anilin-safranin and gentian-violet; iron- 
alum-haematoxylin; and anilin-safranin and iron-alum-haema- 
toxylin. 
ANILIN-SAFRANIN, GENTIAN-VIOLET. 
1, Anilin-safranin alcoholic (50 per cent.) solution prepared by combining 
equal parts of anilin water, and saturated alcoholic (95 per cent.) solution of 
safranin. 
2. Gentian-violet 2 per cent. aqueous solution. Stain from two to four 
hours in the safranin, and from two to four minutes in the gentian-violet. 
The slides must be taken through the alcohols quite rapidly or the stain will 
be lost. 
HEIDENHAIN’S IRON-ALUM-HAEMATOXYLIN, 
1, Ammonio-sulphate of iron 2 per cent. aqueous solution. 
2. Haematoxylin, a % per cent. solution obtained by dissolving in hot 
water. 
Keep the sections from two to four hours in the iron-alum, and then from 
eight to twelve hours in the haematoxylin, afterwards taking out the excess 
of stain with the iron-alum until the sections are of the proper color. 
ANILIN-SAFRANIN, IRON-ALUM-HAEMATOXYLIN. 
This was by far the best combination used, bringing out with remarkable 
distinctness chromatin network, chromosomes, nucleoli, spindles and centro- 
spheres. The centrosomes were especially distinct in some pollen mother 
cells of Sagittaria variabilis, showing as large, black, spherical granules at 
the poles of the spindle. The sections are stained in the usual way in the 
anilin-safranin for two or three hours, and then carried through the iron-alum- 
haematoxylin in the same manner as when this combination is used alone. 
This method, although tedious, will amply repay in results for the long time 
necessary for the staining. The combination is improved a little, perhaps, by 
staining for two minutes after the anilin-safranin in gentian-violet. 
The material was imbedded in paraffin, sectioned from 10-184 
_thick and stained on the slide. 
The root tips of Allium Cepa L. are very favorable objects — 
for the study of karyokinesis, and in making a critical investiga- 
tion of the structures and activities of the cell during division 
hy 
