PLATE VII. 



DISSEMINATION OF THE BACTERIA. 



From photo-micrographs made in New Orleans. Copied by permission 

 of the National Board of Health. 



FIG. 1. Spirillum (Sp.?) from water of salt marsh, near Salem, 

 Mass. X 400 diameters by Beck's | in. objective. 



FIG. 2. Bacteria in distilled water (see note on page 107). 

 X 1,000 diameters by Zeiss's -j^ in. objective. 



FIG. 3. Leptothrix buccalis, epithelial cell, etc., from human 

 mouth. X 1,000 diameters by Zeiss's -fa in. objective. 



FIG. 4. Bacteria from human foeces. X 1,500 diameters by 

 Zeiss's -fa in. objective. 



