184 STATE BOARD OF AGR I CULTURE. 



identify or describe them and to make experimental butters inoculated with 

 those capable of producing off -flavors in milk. 



Besides the work mentioned above some studies are being made upon the 

 ability of spores and dead bacterial cells to release enzymes significant for 

 the spoilage of butter. This work has not progressed to the stage where 

 definite statements can be made. 



In conclusion I should like to quote the last two paragraphs of my report 

 last year. I feel more strongly on this matter now than I did then. The 

 work on enzymes has called for a considerable number of chemical analyses 

 which could have been done much better by a chemist than by a bacteriolo- 

 gist. The work on metalUc salts in butter has been delayed while waiting 

 for favorable action on my recommendation of last year, which follows : 



"I suggest that it would be well to ask the Chemistry Section to co-operate 

 with us on this problem, even to the extent of becoming jointly responsible 

 for the project (Adams lb). I find it impracticable to do the necessary 

 chemical work myself. At the present time it is desirable to determine 

 whether certain off-flavored butters have appreciable amounts of iron, copper, 

 lead or zinc salts present and, if so, to what extent. Some of the work which 

 I have done, and work done at other places, suggests that these salts are the 

 exciting cause of certain ofT-flavors, notably metallic and tallowy flavors. 

 A large number of samples of butter should be examined for their content of 

 these metals and experiments should be performed to show the amounts re- 

 quired to produce the results, the chemical reactions taking place and the 

 conditions which determine what takes place. 



"It would be advantageous also to have the Dairy Section partly responsible 

 for the project, since they are in closer touch with the buttermaking industry 

 and could give the work a practical direction and interpretation, as well as 

 assist us in the manufacture of experimental butters and in the judging of 

 the butters being studied." [G. L. A. Ruehle.] 



Dr. Snyder has taught the Short Course Students in General Bacteriology 

 and has supervised the work of Mr. Davenport until this spring. He has 

 also directed the work of graduate students in Soil Bacteriology. Most of 

 his time has been devoted to his major problem, "The decomposition of 

 peat." He is making very satisfactory progress toward a solution of the 

 problem. 



