Mat 29, 1914] 



SCIENCE 



801 



the cheese, according to the classification as de- 

 termined by the fermentation in broth containing 

 carbohydrates or related substances. The flora of 

 pasteurized-milk cheese is shown to depend upon 

 the organisms introduced in the starter, with the 

 exception of the Sact. casei group, which develops 

 slowly and is concerned with the production of 

 the biting flavor in mature cheese. 



Many experimental pasteurized-milk cheeses 

 were made with starters consisting of the organ- 

 isms isolated from normal raw-milk cheese, either 

 in pure culture or in varying combinations. The 

 results of these experiments showed that pro- 

 nounced difEerences in the flavor could be brought 

 about by varying the cultures in the starter. Cer- 

 tain combinations in the starter resulted in an im- 

 provement of the flavor. 



Technio 

 The Application of Practical Becords to the Main- 

 tenance of StocTc Bacterial Cultures: L. T. 

 Clark and W. L. Dodd. (By invitation.) 

 The scope of a bacterial culture bureau has been 

 gradually broadened, as new organisms have been 

 isolated requiring additional tests to differentiate 

 between old and new species. To assist in their 

 classification a practical system of records is a 

 necessity and to this end the writers submit a 

 method which has had three years' application. 

 Essentially it consists of a double system of 

 records: one, a card index, consisting of classifi- 

 cation charts which provide for the morphological, 

 cultural and biochemical characteristics as well as 

 space for the name, age, source and number of the 

 organisms in question. The auxiliary system is a 

 book record of the cultures in numerical rotation. 

 To avoid confusion resulting from maintaining 

 cultures on the shelves in numerical sequence, an 

 arrangement in groups according to biochemical, 

 morphological and cultural characteristics has 

 been found convenient. Protection from light 

 and dust is provided by means of the black boxes 

 described by Novy. The variable requirements of 

 organisms make it necessary to transplant them at 

 intervals ranging from three weeks to a week or 

 less. Growth of stock anaerobes is established in 

 a volume of pure hydrogen gas. Most pathogenic 

 types may be grown for the first twenty-four 

 hours at incubator temperature, after which they 

 are easily maintained at ordinary room tempera- 

 ture. Saprophytic cultures are kept continuously 

 at room temperature. A duplicate set of cultures 

 is maintained at a low temperature. 



The following advantages may be claimed for 



the system as outlined: The history of the culture 

 forms a part of the record and is readily avail- 

 able; the cultures are easily handled and trans- 

 planted; any one of the organisms may be easUy 

 and quickly located by its number, name or by 

 some predominant biologic characteristic. 



The arrangement in groups, of cultures of simi- 

 lar characteristics, facilitates a further and more 

 complete classification. This leads to the detec- 

 tion of variations between strains of the same 

 species. 



A Study of the ' ' Tellurite Reaction ' ' with the 



Colon-typhoid Group and other Organisms: 



Lewis Davis. 



The writer has investigated the reaction of po- 

 tassium tellurite with the more important mem- 

 bers of the colon-typhoid group and allied organ- 

 isms, with the view of determining: 



(a) DifEerences in antiseptic action on the va- 

 rious members of the group; (6) variations in the 

 macroscopical appearance, character and velocity 

 of the "tellurite reaction" under optimum con- 

 ditions; (c) the influence of treatment with tel- 

 lurite on the biochemical activities of the organ- 

 ism. 



The bacteria studied included the following, ar- 

 ranged in the order of their resistance to the anti- 

 septic action of potassium tellurite: B. capsulatus 

 mucosus, B. capsulatus, B. coli communis, Baot. 

 (lactis) aerogenes, B. cloacce, B. proteus vulgaris, 

 B. paratyphosus "B," B. of swine plague, B. 

 enteritidis, B. typhosus, B. paratyphosus "A," S. 

 paracolon, B. acidi lactici, B. cholerce suis, B. 

 rhinoscleromatis, B. pneumoniae, Boot, dysenteries 

 (Shiga), B. icteroides, Baot. dysenterice (Flexner) 

 and B. zopfii. The variations in resistance to pro- 

 tassium tellurite, as well as in the appearance of 

 their reaction with this salt, are considered suffi- 

 cient to suggest the use of the tellurite for dif- 

 ferential diagnosis within the colon-typhoid 

 group. 



The intensity of bacterial action on potassium 

 tellurite was found to depend upon the individual 

 resistance of the bacterium and the concentration 

 of the salt present. The velocity of reduction of 

 the tellurite is considered to be a specific function 

 of an organism apart from its resistance to anti- 

 septic action. Most of the types studied showed 

 a reaction within thirty minutes. With the colon 

 bacillus the reaction was almost instantaneous. 

 Comparison was made of the action of "tel- 

 lurited" ^ad normal bacteria with dextrose, lac- 

 tose and saccharose bouillons, respectively, as well 



