PLATE VL 



From photo-micrographs made in Havana and New Orleans. Re- 

 produced by permission of the National Board of Health. 



FIG. 1. Spiroch&te (plicatilcf). From foul bilge-water, Hav- 

 ana, Sept. 1879. X 1,450 by Zeiss's T \ in. objective. 



FIG. 2. Vibrios from water of harbor, Havana, near discharge 

 of sewer, Aug., 1879. X 1,450 diameters by Zeiss's ^ in. 

 objective. 



FIG. 3. Sarcina (sp. ?). From standing water in flower-vase, 

 Lafayette cemetery, New Orleans, April, 1880. X 400 diameters by 

 Beck's \ in. objective. 



FIG. 4. Spirillum (volutans ?). From foul gutter- water, New 

 Orleans, May, 1880. X 600 diameters. 



