EXPERIMENT STATION BULLETINS. 523 



to recall a few fermentations similar to the one studied in the hope of correcting 

 any false or dwarfed ideas the reader may gather in a very limited survey, as 

 represented in this work, of a single section of a very broad territory. 



The nature of vinegar fermentation has long been known. In it is found that 

 peculiar dependence of the acetic micro-organisms upon the yeast cells or, in other 

 language, the alcohol produced by the yeast cells* is essential to the proper 

 development of the acetic germs which convert it into acetic acid in the manu- 

 facture of vinegar. This association is required to incite satisfactory fermentative 

 results which we have learned to look upon as constant if suitable conditions are 

 observed. By the work of Nenckif with the bacillus of symptomatic anthra.K 

 and micrococcus acidi paralactici was demonstrated that, by combination or asso- 

 ciation in culture, changes were wrought which could not be accounted for by 

 the cultivation of either germ under isolated conditions and which could be 

 measured by the formation of butyl alcohol over the products of each in separate 

 culture. Burri and StutzerJ have shown that the colon micro-organism exerts a 

 favorable action in the process of denitrification, causing the liberation of an 

 abundance of free nitrogen from sodium nitrate when cultivated with Bacterium 

 denitrificans I, but when each is cultivated in pure culture by itself, neither the 

 colon nor denitrificans I is able to set free nitrogen as indicated in combination. 

 The formation of nitrates from nitrites, and nitrites from ammonium salts 

 through the co-operation of nitroso-and nitro-bacteria, following upon the degi'ada- 

 tion of nitrogenous organic matter by other - classes of bacteria, confirms this 

 interdependence of bacterial action, one species upon the other, and establishes 

 the biological agent as causative and progressive, energetic and eminently capable 

 of instituting many inter-and intra-molecular changes in nature. In the decom- 

 position of meat there appears not a single biological factor, but several seem 

 necessary to the destruction which passes from complex combinations of atoms 

 through a series of steps to simple combinations It is generally accepted that 

 many of the pathogens frequently become more forceful § in the production of their 

 definite pathologic changes through the instrumentality of some non-pathogen, 

 or some other pathogen; in other words, a mixed infection may give rise to a 

 more drastic type of disease; that is, association of two species may greatly in- 

 tensify the power of one to cause abnormal processes. So important and so 

 practical is this that secondary infectious are carefully guarded against, lest 

 primary abnormalities become aggravated. In milk the kephirt granule has 

 long been known as a combination of biological elements. Attempts to ascer- 

 tain specific isolated individual action have been more or less futile. The 

 koumiss starter is not confined to the functional capacity of a single micro- 

 organism, but reaches into associative growth. Ginger-beer** is also recognized 

 as the product of dual capacities, and believed the result of more than a single 

 micro-organism. The antagonistic or associative influence of lactic bacteria over 

 other bacteria is well known, but so far as the writer is cognizant, nothing has 

 been done to demonstrate the favoring influence of some bacteria over the lactic 

 germ. From this curtailed review, such relationship may be considered not as an 

 impossibility; it has been our aim throughout these investigations to positively 

 demonstrate this association and relationship and in this we have not been 

 disappointed; also, we hope to further indicate several dependent, accompanying, 

 and conti'olling circumstances. 



*Pasteur, L. ' 'Etudes sur le vinaigre." (1868). 



fNencki, M. von und Sieber, N. Ueber die Bildung der Paramilclisaure durch Gahrung des Zuckers. (Sitzungsbericht d. kaiser 

 Akad. d. Wissenchaften in Wien. Math. Naturw. Kl. (1889, Mai.) 

 —Cent. f. Bakt. I, Bd. VII (1S90), No. 4, S. 130. 



—Cent. f. Bakt. I, Bd. XI (1892), No. 8, S. 225. Ueber Mischkulturen. 



JBurri, R. und Stutzer, A. Cent. f. Bakt. I, Bd. XVI, No. 20 B. 814. Ueber einen interessanten Fall einer Mischkultur. 

 §Vaillard et Rouget. Annales dl 'Institut Pasteur, T. VI, No. G. Review, Hyg. Rund. Jahrg 1893, S. 80. 

 Novy. Zeit. f. Hvg. u. Inf., Bd. XVII, Heft 2. 

 Funk. Zeit. f. Hvg. u. Inf., Bd. XMI, Heft 3. 

 Ehrlich. Cliarite-Annalcn. VII, Jahrg., S. 223. 

 Roux ct Yersin. Annales de I'lnstitut Pasteur, 1890, T. IV, No. 7. 

 Schreider. Cent. f. Bakt., Ed. XII (1893). No. 9, S. 289. 

 Barbier. .Archive de Med. Experim. 1891. 



IINencki, F., und Fabian, A. Cent. f. Bakt. I, Bd. II (1887), No. 18, S. 523. 

 **Ward, Marshall. Phil. Trans. Roy. Soc. B., 1892, 125. 



