ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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pouring over them concentrated acetic acid in volumes equal to or 
double that of the sea-water containing them. Dorids should first he 
narcotized by gradually adding 70 per cent, alcohol to their sea-water, 
and then killed with concentrated acetic acid or boiling sublimate. 
The larger forms may be killed in 1 to 5 per cent, chromic acid. 
Pteropods are preserved well in Perenyi’s fluid for 15 minutes, 
whence they are passed to 50 per cent, alcohol. Gymnosomatous forms 
should be first narcotized with 1 per cent, chloral hydrate, and then 
killed in acetic acid or sublimate. 
Decapod Cephalopods may be fixed directly in 70 per cent, alcohol, 
making an opening on the ventral surface to allow the alcohol to reach 
the internal parts. 
Bryozoa. — The genera Pedicellina and Loxosoma may be left for an 
hour in 1 per cent, chloral hydrate, and then killed with cold corrosive 
sublimate, washing them immediately afterwards. Some species of 
Bugula give good results when the expanded animals are suddenly killed 
by pouring over them hot corrosive sublimate. With other forms it is 
sometimes possible to preserve them well expanded by adding 70 per 
cent, alcohol gradually to the surface of the water in which they are, or 
by narcotizing first in weak chloral hydrate or in alcoholized sea-water. 
The results are, however, uncertain, and depend largely on the skill of 
the preparator. Brachiopoda may be treated in the same manner as 
Lamellibranchs. 
Tunicates. — Clavellina , Perophora , and Molgula may be killed with 
the orifices expanded by immersing them in 1 per cent, chloral hydrate 
for 6 to 12 hours. They should then be killed in chromic-acetic mixture 
No. 2, and quickly transferred to 1 per cent, chromic acid, injecting some 
of the fluid into the body. After half an hour they should be transferred 
to 35 per cent, alcohol, the injection being repeated, and finally to 
70 per cent. Other simple forms may be treated in the same manner, 
or may require the 2 per cent, solution of chloral hydrate, or may be 
killed by pouring a little 1 per cent, chromic acid on the surface of the 
water in which they are, subsequently hardening in 1 per cent, chromic 
acid. The method recommended for Perophora may be employed for 
compound Ascidians, using, however, corrosive sublimate instead of the 
chrom-acetic mixture. 
Salpee vary considerably in consistency, according to the species, and 
different methods are consequently required. The denser forms, such 
as S. zonaria , should be placed in a mixture of 100 ccm. fresh water 
and 10 ccm. concentrated acetic acid, where they should remain for 
15 minutes. They should then be washed in fresh water for 10 minutes, 
and pass gradually into alcohol. Less dense forms such as S. democratica 
mucronata , may be fixed in chrom-acetic mixture No. 1, and then passed 
directly into fresh alcohol ; while the soft forms such as S. pinnata and 
maxima , should be placed in chrom-osmic mixture for 15 to 60 minutes, 
then washed in fresh water, and transferred to weak alcohol. 
Fishes. — Amphioxus will die with the buccal cirri distended in sea- 
water alcoholized to 10 per cent. They should then be transferred to 
50 per cent, alcohol, and gradually to 70 per cent. 
Other forms may be preserved in alcohol (70 per cent.), taking care 
to make a ventral incision, and also to inject the alcohol and renew it 
