XV] ANAEROBIC BACILLI 391 



the fact that in the above microscopic specimens no Clos- 

 tridia could be discovered, Bacillus amylobacter being 

 noted for the Clostridia forms of its sporing bacilli. The 

 first species, viz., the Bacillus mesentericus, could with pro- 

 bability be excluded from the microscopic examination of 

 fresh specimens alone, since its bacilli show conspicuous 

 motility, whereas in our cases the motility of the bacilli was 

 extremely feeble and could be recognised only on very few 

 examples. But the culture test soon proved that our spores 

 were not those of Bacillus mesentericus. Aerobic gelatine 

 and Agar plates, surface cultures on gelatine and Agar, 

 brought forth the colonies of Bacillus coli only ; the Bacillus 

 mesentericus being aerobic, if it had been present in the 

 evacuations, would undoubtedly have made its appearance 

 in these cultures. More direct proof, however, was ob- 

 tained by placing a mucus flake of the evacuation in gelatine 

 or Agar, heating these to 78-80° C. for ten to fifteen minutes, 

 then preparing ordinary aerobic plates and incubating them 

 at 20° and 37° C. respectively ■ no colonies of any descrip- 

 tion made their appearance. The spores of Bacillus mesen- 

 tericus, like other well-known spores (of Bacillus subtilis, 

 of Bacillus anthracis, of tetanus, of quarter evil, of malignant 

 oedema, &c.) when heated to 80° C. for ten or fifteen 

 minutes do not hereby lose their power of subsequent ger- 

 mination, although all non-sporing bacilli — e.g., Bacillus 

 coli — are thereby killed. Since then in the aerobic plates of 

 the heated gelatine and Agar no growth took place, there 

 could not have been any Bacillus mesentericus present. 

 Besides the above aerobic, also anaerobic cultures were 

 made of the evacuations ; a flake was placed into grape- 

 sugar gelatine and grape-sugar Agar, heated to 78-80° C. 

 for ten to fifteen minutes, then allowed to set and incubate. 

 In both the sugar gelatine and sugar Agar cultures already 



