1918] DAIRY FARMING DAIRYING. 479 



flora of the udder of cows, and gives results of investigations at the Agricul- 

 tural High School of Milan from which it is concluded that the Importance of 

 the microflora of the udder increases as milking approaches the ideal condi- 

 tion ©f absence of external microbial contamination. The microorganisms of 

 the udder are most often found grouped in albuminous clots, which not only 

 makes their enumeration diflicult, but also gives them a marked power to resist 

 heat, although the^' are not sporulating. The microflora of the udder are not 

 affected by the hygieuic condition of the cow sheds, and for this reason bac- 

 terial counts of milk may not give a true indication of the cleanliness of the 

 milking process. The microflora of the udder seem to be connected with ex- 

 ternal and internal factors which still require to be investigated. AVith cer- 

 tain cows the quantitative and qualitative examination yield such persistently 

 high results that the condition may almost be described as abnormal though 

 not pathological. 



For the production of sanitary milk, especially for the feeding of infants 

 and invalids, the author proposes that in the selection of cows not only their 

 state of health but also the microflora of their udders should be taken into 

 account. In the examination of udder microflora the ordinary methods of cul- 

 ture on artificial media can not be used. It is suggested that aseptically 

 drawn milk be examined by the fermentation test, which should be carefully 

 standardized. 



What is meant by " quality " in milk, H. A. Haeding, R. S. Breed, W. A. 

 Stocking, je., and E. G. Hastings {Illinois Sta. Circ. 205 {1917), pp. 3-16). — 

 This analysis of the problem by the committee on milk quality of the American 

 Dairy Science Association contains a brief summary of previous work on 

 various phases of the question, a plea for a broader consideration of the problem 

 of milk quality, and suggestions regarding future progress in improving city 

 milk supplies. The elements of quality in city milk are summarized under the 

 headings of food value, healthfulness, cleanliness, and keeping quality. An 

 outline for grading milk is proposed. 



Enzyms of milk and butter, R. W. Thatcher and A. C. Dahlberg ( U. S. 

 Dept. Agr., Jour. Agr. Research, 11 {1911), No. 9, pp. ^Sl-IfSO) .—AX the Minne- 

 sota Experiment Station several lots of butter were prepared under carefully 

 controlled conditions of manufacture, and held in cold storage in order to 

 study the effect of varying methods of manufacture and storage upon the 

 keeping qualities of the butter. A study of the enzym content of the butter 

 after storage is here reported. 



Deterioration in quality of butter during storage has been considered by 

 some investigators to be due to the action of enzyms contained in it. Fat- 

 splitting (lipase) or protein-hydrolyzing ("galactase" or casease) enzyms 

 have been suggested as possible agents in causing deterioration. The authors 

 state that lipases are present in butter in very small amounts, if at all, and 

 that they could not be conceived to be sufficiently active at the low temperature 

 used in butter storage to cause any appreciable change in the quality of the 

 butter. The protein-hydrolyzing enzym was found to be completely inhibited 

 by sodium chlorid in the concentrations which are present in the water con- 

 tained in all normally salted butters. This fact, together with the known in- 

 hibiting effect of low temperatures upon proteolysis by enzyms, makes it im- 

 possible that the hydrolysis of proteins in the butter by enzyms plays any part 

 in deterioration changes. 



" Proteolysis in skiiu milk was completely inhibited by 1 per cent of chloro- 

 form and by 15 per cent of sodium chlorid. Galactase can not act in normal 

 butter because of the high salt content. In the separation of milk the factors 



