Cultivation 



429 



Fig. 149. — Bacillus diphtherias, five 

 hours at 36°C. This shows only solid 

 staining forms. 





Fig. 151. — Bacillus diphtherias, same 

 culture,- 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. 150. — Bacillus diphtherias, same 

 culture, eight hours at 36°C. This also 

 shows solid forms, many of them with 

 parallel arrangement. 



•♦*»» 







X 







Fig. 152. — Bacillus diphtlieriffi, same 

 culture, fifteen hours at 36°C. The 

 bacilli stain more unevenly and the gran- 

 ules are larger. 



i •? 







J" "^, 





^,^'8- 153.— Bacillus diphtheria, same 

 cmture, twenty-four hours at 36°C. This 

 snows clubbed and barred forms as well as 

 granular forms. At the lower part of the 

 new IS a_ paired form which shows the 

 cnaracteristio clubbing of the distal ends. 

 Air ''?'°™'<=rographs by Mr. Louis Brown. The magnification is the same in all— X 2000. 

 fui or the preparations werel made from growth on blood-serum.) (Francis P. Denny, in 

 Jour, of Med. Research.") ' ^ ' 



Fig. 154. — Bacillus diphtheriae, forty- 

 eight hours at 36°C. This is the same 

 bacillus as in the preceding figures, but 

 from a culture where the colonies were 

 discrete. It shows long filamentous forms. 



