PREFACE TO THE TENTH EDITION. 



This text was originally the outgrowth of a series of 

 lectures on the subject of dairy bacteriology to practical 

 students in the winter Dairy Course in the University 

 of Wisconsin. The importance of bacteriology in dairy 

 processes has now come to' be so widely recognized that 

 no student of dairying regards his training as complete 

 until he has had the fundamental principles of this sub- 

 ject. 



The aim of this volu*me is not to furnish an exhaus- 

 tive treatise of the subject, but an outline and sufficient 

 detail to enable the general student of dairying to ob- 

 tain as comprehensive an idea of the bacteria and their 

 effects on milk and other dairy products as may be pos- 

 sible without the aid of laboratory practice. When pos- 

 sible the dairy student is urged to secure a laboratory 

 knowledge of these organisms, but lacking this, the stu- 

 dent and general reader should secure a general "survey 

 of the field of bacteriology in relation to dairying. 



In this, the tenth edition, the effort has been made 

 to include all of the recent developments of the subject. 

 Especially is this true in regard to the subject of mar- 

 ket milk, a phase of dairying that has gained greatly 

 in importance in the last few years. The changes in 

 the methods of handling market milk have been marked. 

 The results of these changes in influencing the quality 

 of milk offered to the consumer are fully discussed. 



333969 H. L. R. 



E. G. H. 



