PLATE 23. 

 Bacterium violaceum (J. Schroter). Lehm. and Neurn. 



I. Gelatin stab culture, ten days at ordinary temper- 

 ature. 



II. Agar streak culture, six days at ordinary temper- 

 ature. The white borders after a longer time become like- 

 wise violet. 



III. Agar stab culture, seven days at ordinary temper- 

 ature. Stab canal. 



IV. Agar stab culture, seven days at ordinary temper- 

 ature. Surface growth. 



V. Agar plate culture, four days at ordinary temper- 

 ature. X 60. Superficial and deep colonies. Within the 

 former is to be seen the original deeply located colony. 



VI. Agar plate culture, eight days at ordinary temper- 

 ature. Natural size. The colonies often also become dark 

 violet. 



VII. Gelatin plate culture. Natural size. Six days at 

 ordinary temperature. The blue zones are not always so 

 intensely colored. 



VIII. Gelatin plate culture, six days at ordinary temper- 

 ature. X 60. The smaller colony lies near the surface, 

 the larger is on the surface. 



IX. Microscopic preparation. X 700. From a five- 

 days'-old agar culture. 



X. Potato culture, six days at ordinary temperature. 

 XI. Bacteria with flagella. X 1000. Stained accord- 

 ing to Loffler. 



XII. Bacteria with flagella. X 1000. From a culture 

 from Sweden. 



XI. XII. 



