PLATE 18. 

 Bacterium coli (Escherich). L. and N. 



I. Gelatin stab culture, ten days at 22. 

 II. Gelatin streak culture, four days at 22. In nature 

 is transparent, resembling mother-of-pearl in iridescence. 

 Compare also Plate 16, vi. 



III. Agar streak culture, four days at 22. Compare 

 also Plate 16, v. 



IV. Agar stab culture, two days at 22. Stab canal. 



V. Agar stab culture, two days at 22. Surface 

 growth. 



VI. Agar plate, four days at 22. X 60. Deep colo- 

 nies. Compare also Plate 14, vi. 



VII. Agar plate, four days at 22. X 60. Part of a 

 superficial colony. May also occasionally present forms 

 like the bacillus acidi lactici. Compare Plate 12, iv; Plate 

 14, vi ; Plate 17, vi. 

 VIII. Agar plate, three days at 22. Natural size. 



IX. Potato culture, five days at 22. May also be 

 paler or more deeply colored. 



X. Bacteria with long flagella of Bacterium brassier 

 atidw. X 1000. Stained according to Loffler. 



XI. Bacterium of pigeon diphtheria surrounded by fla- 

 gella. X 1000. Stained according to LofHer. 



XII. Bacteria with one flagellum, rarely two flagella, of 

 Bad. coli ft unipolaris. X 1000. Stained according to 

 Loffler. 



X. XI. XII. 



