ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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fts a transparent object, or it may be imbedded in the usual way in 
paraffin and sectioned. The sections may be stuck on with the Schalli- 
baum mixture of clove oil and collodion, and though they gradually lose 
colour, are quite useful for a few weeks. 
Demonstrating Axis-cylinders.* — Dr. H. Stroebe demonstrates axis- 
cylinders in the central and peripheral nervous system as follows. The 
specimens are hardened in Muller’s fluid (4-5 months and afterwards for 
a short time in a thermostat). The hardening is completed in spirit and 
absolute alcohol, and the specimen having been imbedded in celloidin 
sections of about 10 y, are cut in the usual manner. The sections are 
stained in a saturated aqueous solution of anilin-blue for from 10-60 
minutes, and then having been washed in distilled water are differen- 
tiated in absolute alcohol to a capsuleful of which 20-30 drops of 1 per 
cent, caustic potash-alcohol have been added. The latter solution is 
prepared by mixing 100 ccm. of absolute alcohol with 1 grm. of caustic 
potash, and allowiug it to stand for 24 hours and then filtering. 
The sections are next washed in distilled water for 5 minutes or so, 
after which they should be of a bright blue hue. They are then contrast- 
stained with a saturated aqueous solution of saffranin diluted with an 
equal volume of distilled water. This takes from 15 to 30 minutes. 
They are next washed to dehydration in absolute alcohol, and then 
cleared up in origanum oil or xylol, and mounted in xylol balsam. 
Staining Crystalloids of Cell-nuclei, f — Dr. A. Zimmermann finds 
that while nuclear crystalloids and nucleoli have very similar tinctorial 
relations, yet there are methods which allow of their being differentiated 
and, further, of showing that they belong to the erythrophilous consti- 
tuents of the nucleus. 
The material was fixed with alcoholic solution of sublimate, with 
absolute alcohol, or with Merkel’s fixative (1 vol. 1 per cent, chromic 
acid, 1 vol. 1 per cent, platinum chloride, and 6 vols. water). 
The preparations were then stained with : 1, acid fuchsin ; 2, acid 
fuchsin-picric acid ; 3, fuchsin-picric acid ; 4, fuchsin-iodine-green (in 
this case the sections, after having been stained with a mixture of 
aqueous solutions of fuchsin and iodine-green, were placed in a solution 
of 100 ccm. alcohol, 1 ccm. acetic acid, and 0 • 1 grm. I, then in xylol, 
and afterwards mounted in balsam) ; 5, anilin-water-safranin (in this case, 
also, the sections were treated with the alcohol-acetic-acid-iodine mix- 
ture) ; 6, hsematoxylin : the solutions used were those known as Mayer’s 
hsemalum, Delafield’s, Ehrlich’s, Friedlaender’s ; 7, hsematoxylin and 
ammonia-sulphate of iron (NH 4 ) 2 Fe 2 (S0 4 ) 4 . When these last were used 
the solutions were first placed for 30 minutes to 3 hours in 2 per cent, 
iron solution, and then in an aqueous solution of pure hsematoxylin for 
1/2-12 hours (4 ccm. saturated alcoholic solution of hsematoxylin, water 
100 ccm.). The sections were then washed with water and once more 
treated with the iron solution, and having been washed in water were 
mounted in balsam. With this method the results vary with the method 
of fixation. 
* Centralbl. f. Allgem. Pathol, u. Pathol. Anat., iv. (1893) pp. 49-57 (1 colrd. pi. , 
2 figs.). t Zeitschr. f. wiss. Mikr., x. (1893) pp. 211-9. 
