30 CYTOLOGICAL TECHNIQUE 



The finished slides of the same material fixed in different ways 

 should be carefully compared by an observer who does not know 

 which is which. There are strong prejudices in favour of parti- 

 cular fixatives, and few cytologists would be able to judge the 

 slides impartially if they knew which fixative had been used in the 

 preparation of each. 



The difficulty of judging electron-micrographs objectively has 

 already been mentioned (p. 9). 



I 



