DIPHTHERIA BACILLUS. 



333 



observed. The rods are straight or slightly curved, and 

 usually are not uniformly cylindrical throughout their 

 entire length, but are swollen at the end or pointed at 



FIG. 43. 



FIG. 44. 



Diphtheria bacilli characteristic in 

 shapes but showing even staining. In 

 appearance similar to the xerosis ba- 

 cillus. X 1100 diameters. Stain, me- 

 thylene-blue. 



Non-virulent diphtheria bacilli, 

 showing stain with Neisser's solu- 

 tions, supposed to be characteristic 

 of virulent bacilli. Bodies of bacilli 

 in smear, faint brown ; points, dark 

 blue. 



FIG. 45. 



Small type of pseudodiphtheria bacilli. X 1000 diameters. 



the ends and swollen in the middle portion. The 

 average length of the bacilli in cultures from different 

 sources frequently varies greatly, and even from the 



