986 EXPERIMENT STATION RECORD. 



Observations were also made on the effect of the period of lactation 

 mid the character of the food. Although individual animals varied 

 greatly, u in the first 5 months the decrease in total milk flow from 

 month to month is proportionately greater than the decrease in the 

 total fat, and hence the average percentage of fat in the milk gradually 

 increases, so that in the fifth month it is 0.5 greater than the average 

 percentage in the first month." For the remaining 3 months the decrease 

 in milk yield and in total fat were relatively the same. 



"The influence of the period of lactation upon the composition of milk, while 

 varying with individual animals, is, therefore, for herds of reasonable size, prac- 

 tically limited to the first 5 months. Hence the main point to observe in attempts 

 to secure uniformity in composition is to evenly distribute the fresh cows introduced 

 into the herd throughout the different mouths of the year rather than to have them 

 all introduced during any 1, 2, or 3 months." 



The experiments on the effect of food included 4 lots of 2 cows each. 

 The effect of substituting silage for dried corn iodder and of adding 

 sugar beets and potatoes with a full ration, limited ration, and no grain 

 was studied in periods of 5 or 12 days' duration. 



" While the results of these experiments as a whole confirm the view now gener- 

 ally held by careful observers, viz, that the character and quantity of food influence 

 the flow rather than the composition of milk, a temporary decrease in fat was 

 noticed when animals were changed from a dry to a succulent ration and one much 

 richer in digestible carbohydrates (sugar)." 



In conclusion the author urges that milk should be sold on the basis 

 of its fat content; "that is, from the food standpoint the retail price 

 should vary with the variation in composition in order that the con- 

 sumer may get what he pays for and the producer may be paid for what 

 he delivers." The author believes that the results of his investigations 

 show that this is entirely practicable as far as the dairyman is con- 

 cerned, and is engaged in devising a system of inspection suited to this 

 plan. 



A flavor-producing micrococcus of butter, S. C. Keith (Tech. 

 (limri., 1<) (18!/7),pp. 247, 248, figs. 2; abst. in Jour. Boy. Micros. Soc. 

 [London], 1897, No. 5, p. 430). — A micrococcus that produces a butter 

 flavor and aroma when grown on milk or cream has been isolated by 

 the author and designated as Micrococcus bwtyri-aroma-facnens. The 

 micrococcus is characterized by usually occurring in pairs, by being 

 nonmotile, measuring from 0.5 to 1;/ in size, and by growing well at 37° 

 and even at 20° C. It is aerobic and liquefies gelatin slowly. On 

 agar its growth is white and abundant. Milk is not coagulated by it ? 

 but is given a slightly sour, pleasantly aromatic butter flavor. The 

 reaction of the milk is acid. 



Pasteurization of milk, C. E. Marshall (Michigan Sta. Bui. 147, 

 pp. 21-18, figs. 3). — The object of this work was to study certain micro- 

 organisms found to be resistant to pasteurization. A new form of 

 sterilizing apparatus is described, consisting of a tall can with a cover, 

 stirring apparatus, and a faucet at the bottom for drawing off the milk. 

 The can is placed in a jacket ami surrounded by live steam. 



