PLATE VII. 



Dissemination of the Bactekia. 



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 fa 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 fceces. X 1,500 diameters by 

 Zeiss's fa in. objective. 



