STAINING OF FLAGELLA 



(a) With a single loopful of this " suspension " prepare 

 a cover-glass film and allow it to dry in the air. 



(b) Fix it by passing it three times through the flame, 

 holding the specimen in the fingers, so as to avoid over- 

 heating. 



(c) Pour a few drops of solution (a) on the film and 

 allow them to act for half an hour. 1 



(d) Wash very carefully in a large excess of distilled 

 water, and then in alcohol. 



(e) Now keep it for three to five seconds in solution (/3). 

 (/) Without washing, pass quickly through solution (ry). 



(g) Wash again in a fresh quantity of solution (/3), 

 moving the specimen about gently and withdrawing it when 

 the solution begins to turn -black. 



(Ji) Wash it thoroughly in several changes of distilled 

 water. 



(i) Dry it carefully between blotting-paper. 



Mount it first in water and examine it with ^ * u - ^ 

 immersion, and if the specimen be satisfactory, 

 mount it permanently in xylol balsam. 



If the flagella are not sufficiently stained, float the film 

 off the slide and begin again at (/). 



Care must be taken to change the nitrate of silver solu- 

 tion as soon as any precipitation shows itself. 



This is an easy and very trustworthy method. 

 1 At a temperature of 60 C. five minutes is sufficient. 



