' 



. 









D 



A 



o 



8 



THE READING BACILLUS 



A. Stained with .silver to show the peritrichous flagella. 



B. Series showing spore formation. Gram's stain. 



(1) Young 1 , dividing bacillus. 



(2) Granulated form, observed in broth culture. 



(3) Dark-staining material beginning to accumulate, near one end. 



[-The young- spore formed and rilled with dark-staining material. 

 \o 



(6) Centrally placed spore, mature. 



(7) The typical mature sporing form. A dark granule is often to be seen at 



each end of the spore. 



(8) Type of bacillus in older cultures (5-7 flays). The body is beginning to 



disappear. 



(9) The final stage. A spore liberated from the remains of the bacillary 



body. 



C. Mature sporing individuals as seen in a hanging drop. 



This corresponds with No. 7 above, which is taken from a stained film. In 

 the living bacillus the body is torpedo shaped, and the spore does not 

 bulge the sides outwards as it appears to do in the dry film. 



D. A typical surface colony on agar. (3-4 days.) 



A, B. C < 3000. !"> X 5 diameters. 



[To face 1*. 216. 



