ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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by immersion in fresh water, at 35°-40° C., for an hour or two. Bemove 
as much as possible of the soft parts. Immerse for any convenient time 
in alcohol in which corrosive sublimate is dissolved. Dry very quickly 
in the hot sun. After thorough drying, the normal colours can be 
reproduced by means of water colours with very good and permanent 
results. 
Satisfactory specimens of Diadema setosum are particularly difficult to 
procure, on account of the delicacy and fragility of the spines. Thrust 
a stout sharpened wire through the anal membrane as the creature lies in 
his natural position in the water; when detached from the bottom, push 
the wire through and make a loop. Suspend the animal for 15 minutes 
in warm fresh water, and in 1 per cent, chromic acid solution in a large 
vessel ; wash in several changes of fresh water after using chromic acid ; 
place for an hour or two in weak alcohol, then for a day or two in 10 per 
cent, solution of corrosive sublimate in strong alcohol. Dry rapidly in 
the sun, suspended by the wire. If the drying be quickly done, the 
spines will retain nearly their normal position. This process, with 
modifications, can be applied to other Echinoids. 
Alcohol specimens should be killed by immersion for a short time in 
0 • 1 per cent, chromic acid solution, or in warm fresh water ; then place 
in weak spirit, and finally in 80 per cent, alcohol. For histological 
purposes Flemming’s chrom-osm-acetic solution gives good results. 
After hardening recalcify in 70 per cent, alcohol to which a few drops 
of hydrochloric or picronitric acid has been added. 
Methods of Examining Zoanthese.*— Prof. A. C. Haddon and 
Miss A. M. Shackleton examined specimens of Zoanthese which had been 
preserved in alcohol. When a sufficient quantity of strong spirit is 
used this answers very well. They stained the objects alive in borax- 
carmine, imbedded them in paraffin, and cut them with a rocking micro- 
tome. The unincrusted and some of the incrusted genera are very easy 
to cut. As a rule, the incrustations from coral seas are calcareous, and 
admit of being readily dissolved away with nitric acid. 
Mode of obtaining Sections of Ovules.f — Herr J. W. Moll recom- 
mends the following method of making sections of ovules : — The ovules 
(Fritillaria imperialis ) are placed for twenty-four hours in Flemming’s 
solution ; after washing with water they are transferred to alcohol of 
about 95 per cent., and are then dissected in alcohol under the lens. 
The parietal protoplasm of the embryo-sac is removed and placed in a 
drop of celloidin and solidified, and the slide is then plunged in alcohol 
of 95 per cent. The thin plate of celloidin containing the material for 
the sections is then detached from the slide and placed in alcohol of 
95 per cent, coloured by gentian-violet for an hour, next in a mixture 
of 6 per cent, of oil of marjoram and 1 per cent of alcohol (95 per cent.), 
and then in pure oil of marjoram until it becomes transparent. The 
plate of celloidin is imbedded in paraffin and cut into thin sections, 
which are mounted in Canada balsam or dammar-resin after staining with 
gentian-violet. The object is to obtain the nuclei in process of division. 
* Scient. Trans. Roy. Dublin Soc., iv. f 1891) p. 611. 
t Bot. Jaarb., xx. (1890) p. 325. See Bonnier’s Rev. Ge'n. de Bot., iv. (1892) p. 81. 
