PRACTICAL FIXATIVE SOLUTIONS 65 



tives for cytoplasmic inclusions. Examples: Helly,^' Champy,^^^ 

 Lewitsky-saline,^°^' ^® Mann/^^ Zenker- without-acetic. 



Group D. Non-coagulants only. This is a small group, adapted 

 to the study of cytoplasmic inclusions. Examples: Altmann,^ 

 Regaud.i^^ 



It is curious that such a high proportion of fixative mixtures 

 contain one or more coagulants. This is probably connected with 

 the predominance of paraffin as an embedding medium. Group D 

 is likely to come to the fore in the future, as new plastics replace 

 paraffin ; but it remains to be seen whether any non-coagulant is 

 as useful as chromium trioxide in the fixation of chromosomes 

 for light-microscopy. 



