BUEEAU OF ANIMAL INDUSTBY. 123 



BRANCH PATHOLOGICAL LABORATORIES. 



The branch pathological laboratory at Chicago has done special 

 work to determine the nature of a certain acid-fast bacillus which 

 was found in the skin, subcutaneous tissues, and lymph nodes of swine. 

 This work is still in progress. Work has also been started to deter- 

 mine the etiology and nature of a softening of bones in cattle. At 

 the present time no definite conclusions have been reached in regard 

 to this condition. 



One hundred and seventy-five specimens were received during the 

 year at the South Omaha branch laboratory. These represented the 

 usual routine conditions calling for the aid of the microscope in 

 diagnosis. 



TESTS OF ABNORMAL MILK. 



The results of investigations made at the Philadelphia laboratory 

 show that the alizarol test as applied to market milk can not be de- 

 pended upon alone to reveal the presence of abnormalities. Many 

 samples were examined which did not react to the alizarol test, yet 

 were found to be defective by one or more of the other methods. On 

 the other hand, most of the samples found to be defective by the 

 alizarol test were also detected by one of the other tests. No relation 

 was found to exist between the alizarol test and the catalase test in 

 the examination of market milk. 



THE BIOCHEMIC DIVISION. 



Dr. M. Dorset has continued in charge of the Biochemic Division. 



RESEARCH WORK ON MEAT INSPECTION. 



Under an order of the Secretary of Agriculture directing a segre- 

 gation, so far as possible, of the regulatory work on the one hand and 

 of the research work on the other, the routine laboratory work re- 

 lating to meat inspection was transferred to the Meat Inspection 

 Division July 1, 1914. The Biochemic Division has continued to 

 carry out research work relating to meat inspection. 



INVESTIGATIONS CONCEENING COLD STORAGE OF MEATS. 



A study of the changes taking place in fresh beef stored at tempera- 

 tures above freezing was completed during the fiscal year, and the 

 data are being checked and tabulated. In this investigation hind 

 quarters of beef were stored at temperatures ranging from 32° to 

 86° F. for periods varying from 11 to 180 days. At the beginning 

 and at the end of each storage period chemical, bacteriological, his- 

 tological, and organoleptic examinations were made of each sample. 

 The conclusions can only be formulated after all data have been tabu- 

 lated and studied. 



It has been generally recognized that natural autolysis probably 

 plays an important part in the changes taking place in meats during 

 cold storage, but experimental evidence on this point has been lack- 

 ing. A series of experiments was therefore conducted to determine 

 the nature and extent of changes which may be brought about in 

 lean muscular tissue of meats by enzyms occurring naturally in the 

 tissues. These experiments have indicated, among other things, that 



