2) Can be used for animals that are 



a) non-contractile, 



b) have no lime, spicules, skeleton or shells. 



3) Fish - use 5% injection through anus. 



4) Place only a few animals in the same jar at the 

 same time and have much fluid in proportion to 

 animals. 



5) Gelatinous animals - use 1-4%. Kill and harden 

 at the same time with formalin plus 1% chromic 

 acid in a ratio of 1:1. 



6) Ascidians and Tunicates - use 2-6% formalin 

 (the softer the animal the weaker the solution) . 



7) To make solutions, use fresh, or best, seawater. 



8) Transfer animals directly from formalin to alcohol. 



9) Effective for killing and hardening certain forms. 

 Advantage - Colors preserved longer in formalin 

 than in alcohol. 



Potassium bichromate 



1) 5% solution used for slowly hardening gelatinous 

 forms especially when it is not possible to use 

 chromic acid. 



2) Caution - A troublesome precipitate is formed 

 when specimens are transferred to alcohol so its 

 use is not recommended. 



3) To bleach forms before placing them in alcohol, 

 use a few drops of concentrated sulphuric acid. 



Tincture of Iodine - USE RARE. 



1) Used in a 35 or 70% alcoholic solution after 



animals have been killed in corrosive sublimate. 



- 57 - 



