Explanation of Plate 20. 



CORYNEBACTERIUM DIPHTHERIA. (Loffler) Lehniann 

 and Neumann. 



(Diphtheria bacillus.) 



I. Glycerin-agar stick culture, twenty days at 22. 



Puncture canal. 

 II. Glycerin-agar streak culture, eight days at 22. 



III. Glycerin-agar stick culture, twenty days at 22. 



Surface. 



IV. Glycerin-agar plate, eight days at 22. x60. 



Deep and superficial colonies. 



V. Glycerin-agar plate, forty days at 22. x 60. On 

 the left side deep-seated colonies ; on the right 

 side deep and superficial colonies. 



VI. Glycerin-gelatin plate, twenty days at 22. 

 Natural size. Superficial and deep colonies. 



VII. Glycerin-gelatin plate, twenty days at 22. x60. 

 On the left side deep-seated colonies; on the 

 right side superficial ones. 

 VIII. Potato culture, fourteen days at 22. 



IX. Microscopical preparation. Pure culture from 



bouillon two days old. x 700. 



X. Microscopical preparation. Pure culture from 

 bouillon. Involution forms. About xl ? 200. 



XI. Individual bacteria. Highly magnified. Sche- 

 matic, 



