272 MANUAL OF BACTERIOLOGY. 



germicides. It grows best at about 30° C. upon the ordinary 

 culture-media; milk is peptonized. Bacillus subtilis may 

 easily be isolated in pure culture by adding finely cut hay to 

 tubes of bouillon; placing these in the steam sterilizer for five 

 or ten minutes; then letting the tubes develop in the incubator. 

 Plates made from the bouillon will probably show colonies of 

 the Bacillus only, as the steam may be expected to have de- 

 stroyed all organisms except its very resistant spores. 



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/ 



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\ 



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fi 



Fig. 59. — Bacillus subtilis. (X iooo.)n 



The hay bacillus has certain congruers, and it is perhaps 

 more correct to speak, as is often done, of the "hay bacillus 

 group" rather than of a special organism. Some of the con- 

 gruers have been found in pure culture in cases of panophthal- 

 mitis following injury. Moreover, injections of cultures of 

 the organism so obtained, produced panophthalmitis in experi- 

 ment animals.* 



*Silberschmidt. Ann. de I'Institute Pasteur. 1903. p. 268. Also see 

 Kneass and Sailer. Univer. Pennsylvania Med. Bull. June, T903. 



