CONTENTS. 



Introduction - t 



General Considerations as to the Need and Action of Reagents. 

 Fixation, definition of 

 Need of fixation 



Necessary qualities of a fixing agent 

 Probable action of a fixing agent 



Chemical theory 



Physical theory 

 Dependence of differential methods on the action of a fixing agent 

 The uses of alcohol : 



As a fixative 



For washing out 



For hardening 



For dehydration 

 "Clearing," why necessary 

 The grades of alcohol, why necessary 

 The preparation of the grades of alcohol 



Formula 



Table .... i 



General Instructions. 



Applicability of the methods given 



Directions for dissection 



Removal of tissue in case of very young animals 



The amount of fluid necessary 



The size of the pieces of tissue to be used 



The times during which tissues may remain in a fluid 



"Replace " and "transfer" 



Clean slides and cover-glasses, why necessary 



Explanation of references 



Economy of time - li 



THE METHODS. 

 I. An Erythrosin-Toluidin-Blue Method. 



A method for the general internal morphology of the neurone, giving 

 the granulation, "neurosomes, "reticulum, and "axone hillock." Also 

 differential for karyokinesis in the nervous system - 15 



II. The Nissl Method. 



A method devised especially to demonstrate the tigroid masses or 

 Nissl bodies of the nerve-cell 21 



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