SAPROPHILIC CLASS CONTINUED. 



99 



Bacillus subtilis (Ehrenb.) Cohn. 

 SYNONYMS. Vibrio subtilis Ehrenberg ; Hay bacillus. 



EXPLANATORY. This is a well-known and widely distributed or- 

 ganism. First described by Cohn in 1872. It is almost invariably 

 found on hay, hence the common name. Its spores, like those of the 

 ''potato bacillus," are very resistant to heat. A pure culture can 

 usually be obtained by making an infusion of hay or straw and 

 heating it to 80 C. for ten minutes. 



REFERENCES. F. Cohn, Beitraege Zur Biologic, Bd. I, 1872, 

 Heft 2, p. 175 ; C. 276 ; L. 170 ; L. & N. 317 ; Mig. 2 : 515. 



MORPHOLOGICAL CHARACTERS : 



SKETCHES. 



1. FORM AND ARRANGEMENT: 



a. Bouillon 



6. Agar 



c. Gelatin 



d. Other media 



2. SIZE: 



3. STAINING POWERS: 



a. Aqueous gentian- violet. . 

 6. Loeffler's methylen-blue. 



c. Gram's stain 



d. Special stains 



4. MOTILITY : 



a. Character of movement.. 

 &. Flagrella stain 



5. SPORES : 



6. SPECIAL CHARACTERS: 



a. Capsules 



&. Involution forms 



c. Deposits or vacuoles 



d. Pleomorphism 



