206 BACTERIOLOGICAL DIAGNOSIS. 



method by which the so-called polar bodies are stained 

 with methylene blue, while the rest of the organism is 

 coloured a faint yellowish-brown with Bismarck brown. 

 Cultures should be made on blood-serum and should 

 not be less than nine nor more than twenty-four hours 

 old. Films are spread in the ordinary way and stained 

 for half a minute in 



Methylene blue . . i gramme. 



Alcohol (96 / ) . . 20 c.c. 



Glacial acetic acid . 50 c.c. 



Water . . . 950 c.c. 



- They are then washed and treated for half a minute 

 with 



Bismarck brown . *. 5 grammes. 

 Water . . . 1000 c.c. 



The polar bodies are small spheres which are con- 

 tained in the bacilli, there being usually two in each 

 bacillus, one at each end. In a film specimen of the 

 true diphtheria bacillus stained in this way they appear 

 as very minute dark blue or black dots, which may 

 easily be mistaken for cocci ; the bodies of the bacilli 

 are often almost invisible. According to some authori- 

 ties the presence of these granules in young cultures 

 of bacilli which present the 'morphological characters 

 of the diphtheria bacillus, is proof of their virulence, 

 whilst their absence proves the cultures to be of the 

 non-virulent " pseudo-diphtheria" bacillus. The method 

 can also be applied to films made directly from the 

 swabs, and recent researches seem to prove that the 

 results thus obtained are of considerable diagnostic 

 value. 



If this method be adopted the films must be very 



