446 JAMES M. SHERMAN 



He further states that the question as to whether bacteria have 

 any beneficial function can not be answered at the present time. 

 Conn (1901) gives the old ideas concerning the supposed roles 

 of microorganisms, and then reviews the work of Babcock and 

 Russell (1900, 1901). His views on the subject may be well exem- 

 plified by the following quotation: 



From all these facts it becomes clear that while this method of pre- 

 paring food is due to a fermentation, it can not be attributed to the 

 growth of microorganisms. It certainly involves other factors, and it 

 is uncertain whether bacteria, or other microorganisms, have anything 

 to do with the process as normally carried out. 



Since the work of Babcock and Russell fifteen years ago, 

 little has been pubUshed on the processes involved in the cur- 

 ing of ensilage. E. J. Russell's work (1908) was in substantial 

 agreement with that of Babcock and Russell, though he thought 

 it possible that bacteria play a minor part. Esten and Mason 

 (1912) considered the process entirely bacteriological. Three 

 chief fermentations were thought to take place: the lactic acid, 

 alcoholic and acetic acid fermentation. The lactic acid fermen- 

 tation was thought to be due to organisms similar to those con- 

 cerned in the sourmg of milk. It was also beheved by these 

 workers that yeasts cause an alcoholic fermentation and that 

 acetic acid bacteria then oxidize the alcohol so formed to acetic 

 acid. Samarani (1913) concludes that the acetic acid fermenta- 

 tion in silage is due to the respiration of the plant cells, while 

 the lactic acid fermentation is due to bacterial action. The 

 organisms responsible for the latter process were identified by 

 Samarani as a bacillus and a coccus which occurred in about 

 equal proportions. The former he designated as the B. acidi- 

 lactici of Hueppe, and the latter was considered identical with 

 the common streptococcus of milk. 



The role of acid producing bacteria of the Bulgarian type 

 in such fermented products as sauerkraut, milk beverages, 

 cheese, etc., is well known. That they should function in silage 

 would appear probable, but until very recently no data were at 

 hand which gave any evidence for such a belief. Although 



