PLATE VIII. 



Formation op Spores in Bacillus. 



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

 produced by permission of the National Board of Health. 



Figs. 1 and 2. — Bacillus (ulna ?) found in blood of yellow- fever 

 patient (post-mortem) five days after collection. X 3,000 diam- 

 eters by Zeiss's ^ in. objective. 



Fig. 1. — Rods joined in leptothrix chain. 



Fig. 2. — A single rod showing spore at one extremity. 



Fig. 3. — Spores of Bacillus developed in rotten potato, New 

 Orleans, April, 1880. X 1,500 by Zeiss's ^ in. objective. The 

 large cells are some species of Saccharomycete, which was also pres- 

 ent in the same specimen. 



Fig. 4. — Development of bacilli from spores, from culture ex- 

 periment with fish gelatine solution. X 1,500 diameters by Zeiss's 

 ^ in. objective. 



