Microscopy. ast 
days the mass is hard enough for sectioning, and may be inclosed 
in elder pith and cut with the microtome. 
ner sections are required than can be obtained in this way, 
the agar block may be imbedded in paraffine in the following 
manner : e block is to be transferred from the 85 per cent. 
alcohol to bergamot oil (twenty-four hours), then direct to soft 
paraffine kept at a temperature of 45°C. After one to two hours, 
the imbedding process may be completed in the usual way. As 
the agar is saturated with paraffine, very fine sections may be 
obtained ; and these may be freed from paraffine with the usual sol- 
vents, and then stained. 
4. Sections may be clarified, preparatory to mounting, in bal- 
sam or damar, in clove oil, origanum oil, bergamot oil, creosote, 
nase Xylol alone should not be used, as it causes the sections to 
curl. 
Boverrs METHOD oF PREPARING THE Eces OF ASCARIS. 
MEGALOCEPHALA.'—1, The egg-sacks are plunged for a few sec- 
onds into boiling absolute alcohol which contains 1 per cent. 
glacial acetic acid.? The eggs are thus killed instantly, and at the 
same time the egg-membrane is rendered penetrable to the reagents.. 
The alcohol is allowed to cool gradually, and after a few hours the 
eggs are transferred to pure alcohol, colored, and examined in glyc- 
erine or clove oil. This method shows the achromatic spindles and 
a. chromatic ‘equatorial plates, but mot a trace of protoplasmic 
rs 
2. The following mixture was used cold, with excellent results. 
A saturated solution of picric acid is diluted with twice its volume 
of water, and then 1 per cent. glacial acetic acid is added. __ 
e egg-sacks are left at least twenty-four hours in this mixture, 
then washed in 70 per cent. alcohol, stained in Grenacher’s alco- 
p. daaeodor Boveri. Zellen-Studien. Jenaisch. Zeitschr., xxi., 3 and 4, 
* Van Gehuchten calls attention to the fact that acid alcohol was used 
Prof. Tany long before Zacharias published his method. Carnoy 
employed the following mixtures : ; 
absolute alochol......... 6 vol. 
tie acid 
OQIOPOPOPI ein ciciscsiiny edie acne 3 vol 
Chloroform renders the action of the reagent more rapids Vide, La. 
Cellule, t. III., f. 1, p. 6and f. 2, p. 276. a 
