189o.] Microscopy. 859 
Chrom-picric acid. 
I percent.chromie atid o u.a > 
Kleinenberg's picrosulphuric acid ...... | equal sa 
Copper sulphate and corrosive sublimate. 
ro per cent. solution of copper sulphate . . . . . . 100 C.C. 
Saturated solution of corrosive sublimate . . . . . . Ioc.c, 
Potassium bichromate and osmic acid, 
5 per cent. solution of potassium bichromate . . . . . 100 C.C. 
I pet cent, COMIC Was V s... cv "» $6. 
Corrosive sublimate and acetic acid. 
Saturated solution of corrosive sublimate , . . . . . 100 C.C, 
Conteritrated alic ad] 5... eer rr ns SB cc. 
Corrosive sublimate and chromic acid. 
Saturated solution of chromic sublimate . . . . . . IOO C.C. 
ı per cent. chromic acid. . » . + » «es 506 
Frequently great difficulty is experienced in killing an animal with- 
out producing a considerable amount of contraction, and in the case 
of elongated forms, such as Nemertean and other worms, without 
causing them to coil up or become twisted. To avoid this, it is 
expedient to narcotize the animals before killing them, and for this 
purpose Lo Bianco recommends immersion in weak alcohol. He uses 
generaly a mixture of sea-water 1oo c.c. and absolute alcohol 5 c.c. 
In othe? cases 70 per cent. alcohol may be carefully poured upon the 
water in which the specimen lies, so that it forms a layer at the surface. 
It will gradually mix with the subjacent water, and in the course of a 
few hours will narcotize the animal, so that it may be treated with fix- 
ing reagents without fear of contraction. 
Chloral hydrate, ı to 2 parts to 1000 parts sea-water, is also efficient 
as a narcotging agent, and has the advantage of allowing a recovery 
of the animal, if there should be necessity for it, by placing it in fresh 
sea-water. 
For some &ä-anemones tobacco smoke is useful, the smoke being 
conducted by a V-shaped tube into a bell-jar covering the vessel of 
sea-water in which is the anemone. 
Certain of tlese reagents will prove most satisfactory with some ani- 
mals, others with others. Lo Bianco details the best method for treat- 
ing the various fwrms in a second portion of his paper, and an account 
of some of his hethods of procedure, so far as they concern forms 
which resemble thse found upon our coast, may now be presented. 
