1890.] Microscopy. x 863 
time in fresh water, and En into alcohol, taking care to increase 
the strength of this very gradual 
Vermes.—Cestodes, T vine MA Turbellaria, as well as Nemathel- 
minthes, are most satisfactorily killed with corrosive sublimate, either 
cold or hot. „Sagitta, however, succeeds best in copper sulphate and 
sublimate or chrom-osmic mixture. 
Nemerteans should be narcotized in a solution of chloral hydrate in 
sea-water 1 per cent., where they should remain for 6 to r2 hours. 
They are then to be hardened in alcohol. 
Gephyreans may be narcotized with 1 per cent. solution of chloral 
hydrate in sea-water, or in alcoholized sea-water, 3 to 6 hours; or else 
may be killed at once in one-half per cent, chromic acid, which last 
method may also be applied to Hirudinet. 
Chetopods are best narcotized in sea-water containing 5 per cent. of 
absolute alcohol, or by adding gradually to the surface of the sea-water 
in which they are contained a mixture of glycerine 1 part, 7o per 
cent. alcohol 2 parts, and sea-water 2 parts, hardening them subse- 
quently in alcohol. Chetopterus is best killed with 1 per cent. 
chromic acid, in which they should remain for half an hour ; while 
the Hermellidze, Aphroditide, and the Eunicinz may be killed in cold 
corrosive sublimate. Some of these, such as Diopatra, may, however, 
be narcotized in alcoholized sea-water. Serpulide, before treatment 
with corrosive sublimate, should be narcotized in ı per cent. chloral 
hydrate, which causes them to protrude wholly or partly from their 
tubes 
Crustacea.—Cladocera, Copepods and Schizopods may be killed in 
corrosive sublimate, dissolved in sea-water. Ostracodes may be thrown 
at once into 7o per cent. alcohol. Cirripedes die expanded in 35 
per cent. alcohol, and if some specimens contract it is easy to draw 
out the cirrhi with forceps. Amphipods and Isopods may pass 
` directly into 7o per cent. alcohol, except the Bopyrids and Entonis- 
cids, which should be killed in the mixture of equal parts of 9o per 
cent. alcohol and sublimate solution. 
To avoid the casting off of the appendages of the Decapods they 
should be allowed to die in fresh water, care being taken not to allow 
them to remain in it longer than is necessary, as it causes a distortion 
of the membranous appendages. 
cnogonids will die in one-half per cent. chromic acid with the 
appendages fully extended. 
Mollusca.—Lamellibranchs, Prosobranchs and, Heteropods should 
be narcotized in alcoholized sea-water. To avoid the closure 
