800 



SCIENCE 



[N. S. Vol. XXXIX. No. 1013 



The saccharose positive, salicin negative group 

 corresponds to B. communior. 



The saccharose negative salicin positive group 

 corresponds to B. communis. 



The saccharose negative salicin negative group 

 corresponds to B. acidi-lactici. 



Glycerine was found to be of value in separating 

 the cloacEe forms from the aerogenes bacilli, 78 per 

 cent, of the saccharose positive, salicin positive, 

 glycerine negative strains being liquefiers. 



It must be kept in mind, of course, that this 

 classification was obtained with a relatively small 

 number of organisms and can at best be considered 

 only tentative. The results are, however, suffi- 

 ciently interesting to merit further investigation, 

 especially on the part of those interested in the 

 bacteriology of water. Of the dextrose positive 

 lactose negative forms five liquefied gelatine and 

 fermented dextrose and saccharose but failed to 

 ferment any of the other sugars, with the excep- 

 tion of glycerine, which was fermented by two of 

 the organisms. Of the other tests, all were nega- 

 tive with the exception of indol, which was nega- 

 tive for the two glycerine positive organisms and 

 positive for the glycerine negative. For the pres- 

 ent all the five may be grouped under the name B. 

 vulgaris. The sixty-two members of the colon 

 group discussed may, therefore, be said to fall into 

 six main species as follows: 



No. of Or- 

 Speeies Specific Testa ganisms 



B. com- 

 munior dex. +, lac. +, sac, -(-, sal. — , 12, 

 B. oom- 



munis . .dex. +, lac. +, sac, — , sal. +, 11, 

 B. aero- 

 genes . .dex. +, lac. -j-, sac, +, sal. +, 19. 

 B. acidi 



laotici . . dex. +, lac. +, sac, — , sal. — , 

 B. dlo- 



acce dex. +, lac. +, sac, +, sal. -f, glyc. — 



B. vul- 

 garis . ..dex. +, lac. — , sac, +, gel. +, 



A Biochemical Study of Proteins with Beference 

 to the Behavior of Bacteria towards Pure Ani- 

 mal and Vegetable Proteins: Joel A. Spebrt, 

 2d. 



Solutions of unchanged egg albumin, serum al- 

 bumin and edestin were carefully p.-epared. To 

 these solutions sodium chloride, sodium sulphate, 

 calcium chloride and potassium phosphate were 

 added. The composition of these solutions was 

 then of such a character that the bacteria were 

 obliged to break down the protein molecule in 

 order to obtain the necessary nitrogen to synthesize 

 their food in the presence of the inorganic salts. 

 The two most important factors in this investiga- 



tion are: first, that the protein used is really a 

 normal or unchanged protein, and second, that 

 there must be nothing in the final solution from 

 which the organism might obtain the necessary 

 nitrogen, except the native protein. The organ- 

 isms used in this investigation were B. subtilis, B. 

 prodigiosus, B. anthraois, B. proteus vulgaris (two 

 different strains), B. proteus mirabilis, B. coli, B, 

 typhi, B. pyocyaneus, Bacillus "Z," a proteus-like 

 organism isolated from the feces of white rats fed 

 on experimental protein diets, and the anaerobes, 

 B. putrificus, B. anthracis symptomatici, and B. 



Test tubes containing about 10 c.c. of the pro- 

 tein solutions were inoculated from 24-hour slant 

 agar cultures. In making the inoculations every 

 precaution was observed to avoid transferring any 

 of the medium to the tubes containing the protein 

 solutions. Plates were poured immediately after 

 inoculation, and at intervals of 24, 48, 96 hours, 

 and one week; in a few instances ten days and two 

 weeks. The amount of the inoculated material used 

 in the plates was 0.5 c.c. of a 1:10,000 dilution. 

 The plates were incubated at suitable tempera- 

 tures and the number of colonies counted 24 to 48 

 hours later. The period of time during which the 

 organisms survived after being planted in the pro- 

 tein solutions, as shown by the examination of the 

 plates, varied from 48 hours to 10 days. None of 

 the inoculated material gave any visible evidence 

 of decomposition or even putrefaction. Flasks 

 containing 25 c.c. of the different protein solu- 

 tions were inoculated with various organisms 

 and incubated at the optimum temperature 

 for the organism under observation, for a period 

 of two weeks. At the end of this time tests were 

 made to determine the quantity of ooagulable 

 protein. The amount of coagulable protein in the 

 inoculated flasks and the control flasks remained 

 the same, showing clearly that there was no ap- 

 preciable loss of protein. 



A Study of the Bacteria Concerned in the Produc- 

 tion of the CMract eristic Flavor in Cheese of 

 the Cheddar Type: Alice C. Evans and E. G. 

 Hastings. 



A comparative study of the flora of raw- and 

 pasteurized-milk cheese of the Cheddar type has 

 been made, with reference, particularly, to the 

 production of characteristic flavors. The raw- 

 milk cheese flora was found to consist of the fol- 

 lowing four groups of cheese organisms: Bact. 

 lactis acidi, Bact. casei, Streptococci and Mi- 

 crococci. Several varieties of each group occur in 



