58 BACTERIOLOGY. 



in a tuft (lopliotrichic) ; again, they may be seen at both 

 poles; and in some cases, especially with the bacillus 

 of typhoid fever, they are given oif from the whole sur- 

 face of the rod (peritrichic). (See Fig. 7.) In a few 

 instances similar locomotive organs have been detected 

 on spherical bacteria^z. e., motile micrococci have been 

 observed. 



For a long time this property of independent motion 

 could only be assumed to be due to the possession of 

 some such form of locomotive apparatus, because similar 

 appendages had been seen upon some of the large motile 

 spirilla found in stagnant water, but it was not until a 

 few years ago that the accuracy of this assumption was 

 actually demonstrated. By a special method of staining 

 Loffler^ was the first to render visible these hair-like 

 appendages. His method, as well as the several modi- 

 fications that have been made of it, depends for success 

 upon the use of mordants, through the agency of which 

 the stains employed are caused to adhere with increased 

 tenacity to the objects under treatment. 



^Loffler's method of staining will te found in the chapter devoted 

 to this part of the technique. 



