598 



Journal of Agricultural Research 



Vol. XII, No. 9 



of a fermentation curve without the presence of organisms. The value of the curve 

 is, therefore, not an absolute one and no conclusions ought to be drawn without con- 

 sideration of the possibilities of error. 



It would indeed seem that the application of such methods to the 

 study of silage fermentation is entirely without foundation. 



To the evidence in support of the bacterial theory of silage fermenta- 

 tion should be added the very suggestive observation of Clark (4) that 

 the hydrogen-ion concentration of mature silage is coir;cident with the 

 limiting hydrogen-ion concentration obtained in cultures of BacUlus bui- 

 garicus, which organisms are considered by some workers as of para- 

 mount importance in the ripening process. In support of the respiration 

 theory, on the other hand, it is pertinent to call attention to the recent 

 work of Round (12), which indicates that cell respiration is of greater 

 importance in the fermentation of sauerkraut than has been generally 

 recognized. 



It was thought at the beginning of this experiment that a study of 

 the fermentation in silage made from dry stover would throw much 

 light on the nature of the process in ordinary silage. The belief was 

 held that the activity of the plant cells (which have been demon- 

 strated to play an important part in the fermentation of silage made 

 from green com) would be eliminated, to a large extent at least, in the 

 stover silage. But, as may be seen from an examination of the fore- 

 goiag results, the fermentation of ensiled stover appears to resemble, 

 in its main characteristics, that which takes place in green-corn silage. 

 In an effort to determine the factors responsible for the fermentation, 

 laboratory tests were made by ensiling stoVer under different condi- 

 tions. Glass jars containing 175 gm. of cut stover and 400 gm. of water 

 were used. Some were untreated, some put up with antiseptics, while 

 some were sterilized in the aiitoclave and reinoculated with i per cent 

 of raw-silage juice. The results of this study are given in Table V. 



Table V. — Fermentation of stover ensiled under different conditions 



Sample; 

 No. 



Treatment. 



Untreated 



....do 



Sterilized and inoculated 



...do 



2 per cent of toluene 



....do 



2 per cent of ether 



do 



Bacterial count. 



210, 000, 000 



240, 000, 000 



320, 000, 000 



36, 000, 000 



180, 000 



460, 000 



7, 500, 000 



Not made. 



The main points brought out by this test are that stover silage is 

 capable of undergoing a fermentation when preser\^ed with ether, while 

 bacteria alone are apparently unable to produce the typical fermenta- 

 tion, even though conditions are favorable for their active development. 

 The predominating organisms in the sterilized and inoculated samples 



