New York Agricultural Experiment Station. 187 



it early in normal cheese. In these cases, the only difference 

 appears to be the presence or absence of a biological agent. 



What specific organism or combination of organisms may con- 

 stitute this biological factor in cheese-ripening, we are not now 

 able to say. In co-operation with the bacteriological depart- 

 ment of this Station, we have work in progress by which we hope 

 definitely to establish whether these deep-seated chemical changes 

 in cheese-ripening, which can not be attributed to galactase or 

 rennet-pepsin, are due to lactic acid organisms or to liquefying 

 bacteria and their enzymes or to some combination of these. 



