PLATE 63 



Various types of colonies of Bacterium atrofaciens: 



A. — Moderately crowded colonies on agar plate, 3 days old. Oblique light. X 10. 



B. — ^Well-isolated colonies on agar plate, 2 days old. Oblique transmitted light. 

 Xio. 



C. — Single colony on agar plate, 20 days old. Oblique transmitted light. X6. 



D. — Well-isolated colonies on agar plate, 3 days old. Direct transmitted light. 

 Xio. 



E. — Crowded colonies on agar plate, 2 days old. Oblique transmitted light. X 10. 



A and E represent the ordinary type of young colony. B and D are atypical. 



F. — Flagella(Van Ermengem's stain). Stained by M. K. Bryan. Photographed by 

 Erwin F. Smith. About X 2,000. 



