BACTERIOLOGICAL PROCEDURE. 13 



differential media: (1) Plain agar slants, (2) peptonized beef broth, 

 (3) alkaline litmus milk, (4) potato, (5) Dunham's peptone solution, 

 (6) 2 per cent dextrose bouillon, (7) 2 per cent lactose bouillon, (8) 

 2 per cent saccharose bouillon, (9) nitrate broth,, and (10) gelatin, all 

 prepared according to -standard methods. Cultures were observed 

 from one to three weeks, and all except gelatin incubated at 37 C. 



Morphology and staining. In connection with the biological char- 

 acters on culture media the staining and morphological properties 

 were observed with each culture under consideration. 



Motility: Determined in freshly prepared liquid gelatin, or slant 

 agar cultures. 



Staining: Reaction to Gram's stain,, methylene blue, fuchsin,-etc. 

 also stained for flagella when convenient. 



Morphology: Form, arrangement, size, in volution .forms, spores, etc. 



Some bacteriologists consider the great amount of work involved 

 in identifying the individual species of organisms as useless, but the 

 experience of this laboratory is quite to the contrary. Undoubtedly 

 more reliance can be placed upon given bacteriological results, if a 

 more exact knowledge of the contained organism is ascertained than 

 if such a detailed study is omitted. Little is known concerning the 

 specific action of the ordinary organisms such as molds, yeasts, and 

 common saprophytes which are encountered in routine work on food 

 bacteriology, and all information along this line is of value. A 

 thorough study of the chemical nature of the bacterial products 

 elaborated by the growth of saprophytic as well as pathogenic 

 bacteria would also add materially to the value of the results obtained 

 from the biological side of the investigations. These results should 

 be further confirmed if possible by animal inoculation^ with the 

 isolated bacteria or their toxins. 



BACILLUS ENTERITIDIS SPOROGENE8 DETERMINATION. 



From a number of samples of water and oyster liquor 10 cc quan- 

 tities were heated for fifteen minutes at 80 C., and from each sample 

 thus treated 1 cc and 0.1 cc were inoculated into alkaline litmus milk 

 fermentation tubes to determine the presence of the Bacillus enteri- 

 tidis sporogenes. This organism was recorded as being present when 

 the medium coagulated with abundant gas formation within forty- 

 eight hours. Smear preparations from old cultures showed the pres- 

 ence of numerous spore-bearing organisms in the closed portion of 

 the tube. 



DESCRIPTION OF ISOLATED ORGANISMS RESEMBLING BACILLUS TYPHOSUS. 



Four different strains of motile organisms, somewhat resembling 

 Bacillus typhosus, were isolated from samples of water and oysters 

 collected during this investigation. The following general descrip- 

 tion illustrates the character of these organisms: 



