BACTERIOLOGY OF SILAGE 447 



suggestions that these organisms may be of importance in the 

 ensiling of foods are found in the hterature (Heinze, 1913), 

 such suppositions have not been based upon estabhshed facts. 

 The lactic acid bacteria mentioned by Esten (1910) as impor- 

 tant in silage were inhibited by the presence of only 0.45 per 

 cent of lactic acid when grown in corn juice. Gorini (1906) 

 made a detailed study of the bacteria of silage and mentioned 

 Streptococcus lactis-acidi and B. lactis-acidi as the most impor- 

 tant of the acid-forming organisms. None of the organisms 

 which he described had the property of forming a high degree 

 of acidity. Lohnis (1907) in his classification of the lactic acid 

 bacteria described a number of strains of the aciduric bacteria 

 but made no mention of a group derived from silage. Steven- 

 son (1911) studied the distribution of the high acid bacteria 

 but did not report silage as one of the sources from which they 

 were obtained. Heinemann and Hefferan (1909) noted silage 

 as one of the substances from which they had isolated cultures 

 of B. bulgaricus. The recent paper by Hunter and Bushnell 

 (1916) however is the first report, so far as the writer is aware, 

 of the constant occurrence and probable importance of organisms 

 of the B. bulgaricus group in silage. 



OBSERVATIONS 



The notes recorded in this paper are those which have been 

 made on ensilage, more or less incidentally, during the past 

 year. It was first noted on April 26, 1915, that sterilized milk 

 inoculated with silage developed a high acidity. After incuba- 

 tion for ten days at 37°C. the milk was found to contain an acid- 

 ity of 2.3 per cent calculated as lactic acid. This observation 

 indicated the presence of organisms belonging to the group of 

 aciduric bacilh, and these bacteria were isolated from the milk 

 culture by plating on ordinary lactose agar. Their occurrence 

 has been repeatedly verified in samples of corn ensilage from 

 four different silos taken at various stages during the feeding 

 season. 



That the high acid-producing organisms not only exist in 



