ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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should be killed with concentrated acetic acid, and immediately trans- 
ferred to chrom-osmic mixture for fifteen to thirty minutes. The same 
method answers for Cunina, while Liriope should be treated at once with 
chrom-osmic from five to twenty minutes. 
Scyphomedusfe are the best fixed with 1 per cent, osmic acid, to the 
action of which they are subjected until they assume a pale brown tint. 
They should then be thoroughly washed with fresh water before being 
placed in 35 per cent, alcohol, and should be finally preserved in 70 per 
cent. 
Siphonophores. — The forms of this group should be preserved soon 
after capture, and specimens in good condition should be selected. 
Agalma and similar forms should be killed in the mixture of copper 
sulphate and sublimate, which should be used in volume equal to or 
double that of the sea-water in which the animal floats. The mixture 
should be poured in rapidly, and not over the animal. When killed, 
the specimen should be carefully lifted upon a large horn spatula, and 
transferred to 35 per cent, alcohol for a few hours, and then placed in 
70 per cent. It is recommended to preserve the animals in tubes just 
large enough to contain the specimens, and placed within a second larger 
tube. In this way evaporation of the alcohol is prevented, and also 
injury of the specimen from movements of liquid is avoided. 
Physalia should be placed in a cylinder filled with sea-water, the 
animal being lifted by the pneumatophore. When well expanded, it is 
killed by pouring over it the sublimate and acetic acid mixture (one- 
quarter the volume of the sea-water), and when dead, is transferred to a 
cylinder containing one-half per cent, chromic acid, and then after twenty 
minutes to 50 per cent, alcohol, and finally to 70 per cent. 
Velella may be killed with chrom-picric or sublimate and chromic 
acid mixture, and after a few minutes should be transferred to weak 
alcohol. Porpita may be fixed by dropping Kleinenberg’s picro-sulphuric 
acid into the vessel in which it is contained, and when the blue colour 
commences to change to red it should be transferred to Kleinenberg’s 
fluid, and after fifteen minutes to weak alcohol. 
Diphyes may be killed expanded by hot corrosive sublimate. 
Ctenophora may be killed by throwing them into the chrom-osmic 
mixture, where they should remain for fifteen to sixteen minutes, accord- 
ing to the size, and then gradually passing them through alcohol to 
70 per cent. A mixture composed of pyroligneous acid, concentrated, 
1 vol. ; corrosive sublimate solution, 2 vol. ; one-half per cent, chromic 
acid, 1 vol., is also recommended as a fixative. 
Echinodermata. — Starfish may be prepared with the ambulacral feet 
in full distension by allowing them to die in 20 to 30 per cent, alcohol. 
Echinoids should be placed in a small quantity of water, and killed with 
chrom-acetic mixture No. 2, being removed from it as quickly as 
possible, as the acid corrodes the test. To preserve the internal parts it 
is necessary to make two opposite openings in the test, so that the 
alcohol may penetrate the interior readily. 
Holothurians, such as Thyone and Cucumaria, after the tentacles are 
fully expanded, should be seized a little below the bases of the tentacles 
by forceps, using a slight pressure, and the anterior portion of the body 
should then be immersed in concentrated acetic acid. Alcohol (90 per 
