26 Director's Report of the 



many so-called practical feeding experiments have been carried on, 

 and while these are very useful as a test of theories and of formulae 

 based upon severer investigation it is safe to say that they will 

 not form foundation material for the science of cattle feeding. 



bacteriological studies. 



The science of bacteriology has come to have very definite rela- 

 tions to farm practice in several directions. We now know that 

 soil bacteria are important agents in the preparation of plant food. 

 These organisms are intimately associated with the development 

 of leguminous plants such as alfalfa and clover, and one of the 

 triumphs of modern agricultural science is the inoculation of the 

 soil with bacteria as one essential preparation for the growth of 

 alfalfa and other legumes. 



Bam and dairy sanitation, now established on a fairly definite 

 basis, is the outcome of bacteriological investigations ; for it is 

 this class of organisms that is responsible for the degradation of 

 dairy products through undesirable and excessive fermentation, to 

 say nothing of the presence of disease germs. The technical 

 processes used in the manufacture of butter and cheese are based 

 upon fermentative changes caused by lactic acid ferments and 

 other forms of germ life. 



Progress in bacteriological investigation has to quite an extent 

 been limited by the development of methods of work and the ex- 

 tent of our knowledge of the various classes of bacteria and their 

 reactions. For this reason, it has been found necessary and is 

 still necessary to devote much time to the technics of the labora- 

 tory and the study of the various types of organisms irrespective 

 of their economic relations. 



Several years ago the Station began a study of the changes 

 which occur in the curing of cheese, changes brought abcmt 

 through the action of ferments, both chemical and bacterial. In 

 making these investigations it was found desirable to suppress 

 the action of one class of ferments or of all ferments in order to 

 discover, if possible, what agencies were operating to cause the 



