b) Killing. Draw off water but do not uncover 

 animals and flood with 10% formalin. 



c) Store in 5-10% formalin or 70% alcohol. 



3) Other Methods 



a) Add magnesium sulphate crystals gradually 

 or place them in a muslin bag with the 

 specimens. 



b) Poison by adding a few drops at a time of 

 dilute formalin. Double the quantity each 

 time. 



c) Freeze in block of ice, chip off excess ice. 

 Allow to melt in strong formalin. 



d) Draw water down without uncovering animals 

 and kill suddenly with boiling formalin. 



e) Caution . DO UNDER FUME HOOD. 



4) Cnidae 



a) Scrape off ectoderm. Place it in a drop of 



seawater on a slide. Tease apart with needles. 

 Drop over it a cover slip and press up and 

 down to help break up the tissue. With a 

 camel's hair brush transfer the dissociated 

 tissue to clean seawater. Smear a cover slip 

 with albumen. Place a little of the dis- 

 sociated tissue on it and air-dry until tacky. 

 Fix with Schaudinn's fluid for 5-10 minutes. 

 Wash with 50, 70% alcohol; then 70% iodized 

 alcohol. Put in 90% alcohol for 1 hour and 

 stain in light green (0.5% solution in 95% 

 alcohol) for several minutes. Rinse in 

 clean 95% alcohol. Mount in euparal. 



CTENOPHORA 



A) Allow to expand in standing or running seawater. Trans- 

 fer from water to chromo-osmic (chromic acid 1%, 100 ml, 

 osmic acid 1%, 2 ml) for 15-60 minutes, copper sulphate 

 and corrosive sublimate. Pass through 30, 50, 70% 

 alcohol. 



B) Store in 70% alcohol. 



C) Caution - DO NOT STORE IN FORMALIN. 



PLATYHELMINTHES 



A) Turbellaria 



1) Narcotize by placing specimens in salt or fresh 



water depending on the species and add small amounts 



of menthol or chloral hydrate crystals to the 



- 60 - 



