1890. ] Microscopy. 985 
After 24 hours the preparation is washed and placed in 70 per cent. 
alcohol, which is then gradually replaced by a higher grade. For 
staining, Ehrlich’s acid hematoxylin, diluted with half its volume of 
water, is used for five minutes. 
Flemming’s fluid, followed by saffranin, also gives excellent prepar- 
ations. 
Direct Division of the Nucleus.‘— Platner avows his con- 
viction that the nucleus does divide, in some cases at least, without 
any caryokinetic phenomena. ‘This fact, according to Platner, is 
clearly shown in malpighian tubes of insects (e.g., Dytiscus). The 
gland-cells are very large, and their nuclei are often three or more 
times the diameter of the nuclei in Triton cells. The tubular organs 
can be examined in toto without the trouble of imbedding and cutting. 
Kleinenberg’s picro-sulphuric acid is recommended for hardening, 
and borax-carmine for staining. 
Spermatogenesis in the Hermaphrodite Gland of Limax 
` agrestis.5—Platner recommends the following method of preparation 
for the reproductive elements in Limax 
The fresh hermaphrodite gland is placed in the stronger Flemming’s 
fluid for one hour; then three to four times its volume of water is 
added to the fluid, and the object left 24 hours. The preparation is 
then washed in the manner described by Flemming, and passed through 
ascending grades of alcohol. 
The following hematoxylin solution gives the best stain for the 
neben-nucleus : 
Hansen, 10s. zu van Ig. 
Alcohol absol 1749. V redo e e 70 g. 
Le SEs ies IE 
To be kept in a dark bottle. 
The object is stained in toto 24 hours; then decolorized in a 1% 
alcoholic solution of bichromate of potash. For this purpose a 
solution of ro parts of bichromate of potash in 300 parts aq. dest. is 
kept on hand, from which 30 ccm. may be taken each time for use, 
and mixed with 70 ccm. 95 per cent. alcohol. The fluid should be 
kept in the dark during the process of decolorizing, which may require 
from 12 to 24 hours. 
The object is next placed in 70 per cent. alcohol, and kept dark for 
one or more days. Then follows absolute alcohol, cedar oil, and im- 
bedding in paraffine. 
Arch, f. mik. Anat. XXXIIL., 1, 1889, p. 145. 
5 Platner. Arch. f. mik. Anat. XXXIII., 1, 1889, p. 126-7. 
