412 



Diphtheria 



"'' 



Fig. 150. Bacillus diphtheriae, five hours Fig. 151. Bacillus diphtherias, same cul- 



at 36 C. This shows only solid staining ture, eight hours at 36 C. This also shows 

 forms. solid forms, many of them with parallel ar- 



rangement. 



Fig. 1 5 2. Bacillus diphtheriae, same cul- 

 ture, twelve hours at 36 C. The bacilli 

 stain faintly at their ends, and in some small 

 granules are seen at the tip of the faintly 

 stained portions. 



Fig. 153- Bacillus diphtheriae, same cul- 

 ture, fifteen hours at 36 C. The bacilli 

 stain more unevenly and the granules are 

 larger. 



.'<?-.. 



./?' -'V 



Fig. 154- Bacillus diphtheriae, same cul- Fig. 155. Bacillus diphtheriae, forty- 



ture, twenty-four hours at 36 C. This eight hours at 36 C. This is the same 



shows clubbed and barred forms as well as bacillus as in the preceding figures, but from 



granular forms. At the lower part of the a culture where the colonies were discrete, 



field is a paired form which shows the char- It shows long filamentous forms, 

 acteristic clubbing of the distal ends. 



(Photomicrographs by Mr. Louis Brown. The magnification is the same in all X 2000. 

 All of the preparations were made from growth on blood-serum.) (Francis P. Denny, in 

 " Jour, of Med. Research."; 



