136 BACTERIOLOGY. 



lene-blue solution. The spores will be red, the body of 

 the cells blue. 



In this method the object of the preliminary exposure 

 to chloroform is to dissolve away any crystals of lecithin, 

 cholesterin, or fat that may be in the preparation, and 

 which when stained might give rise to confusion. 



Loffler's Method for Staining Flagell^e. — 

 For the demonstration of the locomotive apparatus pos- 

 sessed by motile bacteria we are indebted to Loffler. 

 By a special method of staining in which the use of 

 mordants played the essential part, he has shown that 

 these organisms possess very delicate, hair-like appen- 

 dages, by the lashing movements of which they propel 

 themselves through the fluid in which they are located. 

 The method of Loffler is as follows : 



(1) It is essential that the bacteria be evenly and 

 not too numerously distributed upon the cover-slip. The 

 slips must therefore be carefully cleansed. (See Loffler's 

 method of cleaning cover slips.) Five or six of the 

 carefully cleansed cover-slips are to be placed in a line 

 on the table, and on the centre of each slip a very small 

 drop of tap-water is placed. From the culture to be 

 examined a minute portion is transferred to the first slip 

 and carefully mixed with the drop of water; from this 

 mixture a small portion is transferred to the second, 

 and from the second to the third slip, and so on — in this 

 way insuring a dilution of the number of organisms 

 present in the preparation. 



These slips are then dried and fixed in the ordinary 

 way. They are next to be warmed in the following 

 solution : 



