102 Neurological Technique 



If the foetus is to be kept as a museum specimen, the Kaiser- 

 ling method (XVII, p. 95) is especially recommended as pro- 

 ducing the least amount of change in its normal macroscopic 

 appearances. 



4. Foetuses of from 5 months to term are too large to be 

 fixed in toto. Ten per cent, formalin (D) will come nearer to fix- 

 ing them than any fluid known. If 10 per cent, formalin be 

 injected into the blood vessels and the alimentary tract of even a 

 large foetus, and then the body cavity opened and the specimen 

 placed in the fluid, the specimen will be well preserved for all 

 purposes of dissection, but it cannot be depended upon that the 

 tissues will be sufficiently well fixed for microscopic purposes. 



Formalin used alone as a fixing agent gives better results when 

 applied to the central nervous system than when applied to 

 other tissues of the body (see Methods IX, X, and XIX). If it 

 is especially desired to study the central nervous system of the 

 foetus, either expose it before placing the foetus in the formalin 

 or, better, remove it entire and place it separately in the fluid. 

 Also, if it is desired to study any of the other organs microscop- 

 ically, remove such pieces as are wanted and fix them in a fluid 

 more suited to the purpose in mind. The remainder of the 

 foetus may then be preserved in 10 per cent, formalin. The more 

 exposed portions may be sufficiently fixed for general micro- 

 scopic anatomy, but formalin is by no means recommended for 

 this purpose. 



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