DAIRY FARMING DAIRYING. 373 



of hand-drawn milk. The results obtained in the course of tbe experiments 

 do not indicate that high vacuums or changes in vacuum may of themselves 

 cause the excessive discharge of cells or draw blood from the interior of tlie 

 udder. 



The reasons for the discharge of the two kinds of cellular elements are 

 different. The epithelial cells are presumably discharged because they are 

 worn out iu the process of the secretion of the milk. The reason for the pres- 

 ence of the leucocytes is not so clear. By some investigators it is believed that 

 they are attracted into the milk by the presence of bacteria in the udder, espe- 

 cially by the pus-forming streptococci. The investigations here carried out have 

 not demonstrated what relationship exists, if any does exist, between the num- 

 ber of cells discharged and specific infections of the udder. Enough data were 

 secui-ed, however, to make it probable that tbere are other reasons for the dis- 

 charge of leucocytes in the milk than the presence of bacteria in the udder. 

 These other reasons undoubtedly have to do with the physiological conditions 

 surrounding the process of milk secretion. 



Bacterial and enzymic changes in milk and cream at 0° C, Maey E. 

 Pennington, J. S. Hepburn, E. Q. St. John, et ax. {Jour. Biol. Chem., 16 

 {1913), No. 3, pp. 331-368).— In some previous work (E. S. R., 20, p. 179) it was 

 demonstrated that raw milk held at or a little below a temperature of 0° C. 

 undergoes marked proteolysis, which is very noticeable at the end of 2 weeks. 

 The function of the present research was to determine which part of the proteo- 

 lysis is due to bacteria and Avhich part is due to the euzyms of milk, and, finally, 

 what results when both bacteria and enzyms act together. 



It is shown that the proteolysis of casein is due primarily to bacterial action, 

 while that of lactalbumin is due to the enzyms of the milk. Bacterial and milk 

 enzyms, when active at the same time, cause a greater degree of proteolysis. 

 In the course of proteolysis the true proteins are broken down to caseoses, pep- 

 tones, and then to amino acids. The fermentation of lactose is largely, if not 

 entirely, due to bacterial action. 



" The digestion of the protein, the fermentation of the lactose, and the 

 increase in acidity are progressive changes, and are accompanied by more or 

 less progressive lowerings of the freezing point of the milk. The depression of 

 the freezing point of the cream is to be ascribed to chemical changes in its 

 protein and lactose. ... " During the holding at 0°, the organisms of the raw 

 untreated and reinfected sterile milk and cream undergo an increase, which is 

 most striking in the raw untreated milk." 



[Dairy laws], compiled by L. J. Smith and F. B. Duvaxl (Sess. Lmcs Colo., 

 1913, pp. 231-245). — This is the text of the Colorado laws relating to the 

 regulation of the production, sale, and shipment of dairy products and oleo- 

 margarine, the inspection of dairies, creameries, etc., standards for dairy prod- 

 ucts, rules for sampling, and other related subjects. 



Is the establishment of a uniform fat standard for whole milk practical? 

 O. Mezger (Milchw. ZentU., 42 (1913), Xos. 16, pp. 492-499; 17, pp. 522-528; 

 18, pp. 545-555; 19, pp. 574-580, figs. 4; 20, pp. 609-616, figs. £).— In commenting 

 on the impracticability of a uniform fat standard for whole milk the author 

 cites a number of earlier investigations showing that milk undergoes wide daily 

 and weekly changes due to feeds, lactation period, and other variable factors. 



Principal types of micro-organisms in Baltimore milk, L. P. Shippen 

 (Bui. Johns Hopkins Hosp., 25 (1914), No. 278, pp. 122-128).— It was found 

 that the most frequently encountered organism in the milk examined was 

 BaciUus lacticus, or as the author chooses to term it, Bacterium giintheri. Cer- 

 tain strains of the bacterium resemble Streptococciis pyogenes, but may be dif- 



