ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
133 
is brought back, tho paper again falls on the edge of the paraffin-block, 
and the process can be repeated. 
Another mode of using the instrument, which may be advantageous 
in certain cases, consists in fixing the fork g on the horizontal arm in the 
opposite direction so that the clamp-arm a t of the lever points away from 
instead of towards the microtome. In this case in the forward motion 
of the knife the effect of the paper is to push the section up the blade. 
The thinner the sections, the smaller should be the rider and the 
nearer to tho axis should it be suspended. The kind of paper used should 
also vary with the thinness of the sections. 
(4) Staining- and Injecting-. 
Fiocca’s Method for Spore-Staining.* — Dr. R. Fiocca states that 
by the following method spores can be stained with great efficiency and 
certainty. The reagents necessary for the process are a 10 per cent, 
solution of ammonia, an alcoholic solution of an anilin dye, a 20 per 
cent, decolorizing solution of sulphuric or nitric acid, and an aqueous 
solution of a contrast stain. Into a capsule are poured about 20 ccm. 
of ammonia solution, and then are added 10 to 20 drops of the alcoholic 
solution of the anilin pigment. The solution is warmed until it begins 
to vaporize, and then the already prepared cover-glasses are treated 
therewith in the usual manner. 
On the average, spores are stained in from 3 to 5 minutes, and only in 
the case of very resistant spores, such as anthrax, are 10 to 15 minutes 
required. When sufficiently stained, the preparations are treated with 
the decolorizing fluid; they afterwards are washed in water and then 
contrast-stained. 
For staining spores, alcoholic solutions of gentian-violet, fuchsin, 
methylen-blue, safranin give excellent results ; and for contrast, aqueous 
solutions of vesuvin, chrysoidin, methylen-blue, malachite-green, and 
safranin may be used. 
By this method not only are the spores stained, but those proto- 
plasmic granules which precede spore -formation, while degenerative 
conditions are unaffected. 
As in Gabbett’s formula for bacilli of tubercle the contrast-stain may 
be dissolved in the decolorizing solution ; but in such case the solution 
must be less strong (not more than 10 per cent, of acid), and the pre- 
parations remain therein a correspondingly longer time. 
Employment of Vesuvin for Fossil Plants.! — Herr O. Lignier 
recommends the use of an alcoholic solution of vesuvin for staining 
sections of fossil plants which have first been cleaned by chloroform. It 
is especially useful for bringing out the xylem portion of the vascular 
bundles. 
Demonstrating Intercalary Rings of Nerve-fibres, j — M. B. Segall 
adopts the following procedure for examining medullated nerve-fibres. 
A quite fresh nerve, from a frog or a guinea-pig, a day old, is rapidly 
teased out in a few drops of 1 per cent, osmic acid. When the nerve 
* Centralbl. f. Bakteriol. u. Parasitenk., xiv. (1893) pp. 8-9. 
t Bull. Soc. Linn. Normandie, vi. (1892) pp. 9-10. See Bot. Centralbl., lvi. 
(1893) p. 18. % Journ. Anat. et Physiol., xxix. (1893) pp. 586-603 (1 pi.). 
