Silage Formation 213 



Kature of the changes in the silo. — These changes 

 are very complex. Thej' have been regarded as due to 

 the activity of a variety of ferments, principally those 

 which are believed to cause the formation of alcohol 

 and acetic, lactic and other acids. Whether the oxi- 

 dations occurriug in the silo are wholly induced by 

 ferment action or in part at least are the result of 

 oxidations brought about in other ways is a point over 

 which there has been some recent interesting discussion. 



Babcock and Russell have carried on at the Univer- 

 sity of Wisconsin, able and very suggestive inves- 

 tigations concerning the causes of silage formation. 

 They conclude that the theory that silo changes under 

 normal conditions are due whollj^ to bacteria "does 

 not rest on a sound experimental basis." 



Their data lead them to regard respiratory processes, 

 both direct bj' the plant cells and intramolecular, as 

 the main causes of the chemical transformations Avhich 

 produce carbon dioxid and the evolution of heat within 

 the ensiled mass. The direct respiration appropriates the 

 oxygen confined in the air spaces of the silo, and the 

 intramolecular respiration uses oxygen combined in the 

 tissues. Both forms of respiration go on only so long 

 as the plant cells remain alive. Concerning bacteria 

 the authors say: "The bacteria, instead of function- 

 ing as the essential cause of the changes produced 

 in good silage, are on the contrary only deleterious. 

 It is only where putrefactive changes occur that their 

 influence becomes marked." 



Whatever are the inducing causes, the chemist finds, 

 when he keeps a careful record of what takes place in 



