VITAMINES AND GROWTH OF STKEPTOCOCCUS 463 



possibility suggests that it may he dosinible to study further 

 the vitamine content of mineral oil. Third, that the stimulation 

 with fats and oils containing vitamine-A and that with mineral 

 oils is not due to the same thing. Facts in our possession at 

 present do not suggest which possibility is the correct one. 



SUMM^UIY AND CONCLUSIONS 



1. The results presented in this paper apply only to the growth 

 of a culture of a pathogenic streptococcus and do not necessarily 

 apply to bacteria in general. 



2. Autolized yeast extract contained a growth-promoting sub- 

 stance or substances for the streptococcus studied. Water- 

 soluble B did not, however, appear to be the significant substance. 



3. Cabbage extract was found to promote growth, but a 

 glucose solution containing the same amount of sugar as the 

 cabbage extract showed a similar growth-promoting effect. 

 It is evident that when extracts of plant or anim.al tissues are 

 used the sugar content must be given consideration in connec- 

 tion with their growth-promoting properties. 



4. Fats and oils, vegetable, animal and mineral even in very 

 small amounts were found to stimulate the growth of the strep- 

 tococcus. Either the growth-promoting property of fats and 

 oils is not due to fat-soluble A, or this vitamine is present in 

 mineral oils, or the stimulation is due to different causes in the 

 case of the vitamine-containing fats and oils and the mineral 

 oils. 



REFERENCES 



Agulhon, H., et Leguoux. R., 1918 Contribution a I'etude des vitamines 



utilisables i la culture des microorganismes. Application au bacille de 



I'influenza. (B. de Pfeiffer). Compt. Rend. Acad. Sci. [Paris], 167, 



597-600. 

 Bachmann, F. M. 1919 Vitamine requirements of certain j'easts. Jour. Biol. 



Chem.,39,no. 2,23.5-258. 

 Cole, S. W., and Lloyd, D. J. 1917 The preparation of solid and liquid media 



for the cultivation of the gonococcus. Jour. Path, and Bact., 21, 



no. 2, 267-280. 

 Davis, D. J. 1921 Food accessory factors in bacterial growth. III. Further 



observations on the growth of Pfeiffer's bacillus (B. influenzae). Jour. 



Infect. Diseases, 29, no. 2, 171-177. 



