[15] U. S. Dept. Agr., Farmers' Bul. 602, Dairy Division, Production of clean milk, 1914. Lauder, A., and A. Cunningham, Some factors affecting the bacteriological content of milk, Edinburgh and East of Scotland Coll. of Agr. Rept. XXVIII, 1913. Prucha, M. J., and H. M. Weeter, Germ content of milk, Ill. Exp. Sta. Bul. 199, 1917. Harding, H. A., _et al._, The effect of certain dairy operations upon the germ content of milk, N. Y. Exp. Sta. Bul. 365, 1913. Fraser, W. J., Sources of bacteria in milk, Ill. Exp. Sta. Bul. 91, 1903. Frandsen, J. H., Care of milk and cream on the farm, Neb. Exp. Sta. Bul. 133, 1912. Conn, H. W., The care and handling of milk, Conn. (Storrs) Exp. Sta. Bul. 26, 1903. Stocking, W. A., Jr., Quality of milk as affected by certain dairy operations, Conn. (Storrs) Exp. Sta. Bul. 42, 1906. [16] Harding, H. A., J. K. Wilson and G. A. Smith, Tests of covered milk pails, N. Y. Exp. Sta. Bul. 326, 1910. Stocking, W. A., Tests of covered milk pails, Conn. (Storrs) Exp. Sta. Bul. 48, 1907. [17] Wing, L. W., Milking machines; their sterilization and their efficiency in producing clean milk, N. Y. (Cornell) Exp. Sta. Circ. 18, 1913. [18] Ruddick, J. A., and G. H. Barr, The cooling of milk for cheese making, Ottawa Dept. of Agr. Bul. 22, 1910. [19] Wis. Exp. Sta. Rept. 1895, pages 14-150, Fermentation test for gas-producing bacteria in milk. This is commonly called the Wisconsin curd test. [20] Stevenson, C., Pepsin in cheesemaking, Jour. Agr. (New Zeal.) 14 (1917), pages 32-34. Todd, A., and E. C. V. Cornish, Experiments in the preparation of homemade rennet, Jour. Bd. Agr. (London) 23 (1916), no. 6, pages 549-555. Besana, C., Lack of coagulating ferment in cheesemaking, Staz. Sper. Agr. Ital. 49 (1916), pages 10-12. Van Dam, W., Rennet economy and substitutes, Verslag. Ver. Exploit. Proefzuivelboerderij. Hoorn, 1914, pages 45-46. [21] The paragraphs on the chemistry of casein and on rennet action have been selected from a complete discussion of the subject by E. B. Forbes and M. H. Keith in Ohio Exp. Sta. Tech. Bul. 5 entitled, "A review of the literature of phosphorus compounds in animal metabolism." The original references cited in this discussion are given at the end of the chapter in the order of their citation in the text. See also, Van Slyke, L. L., and D. D. Van Slyke, I, The action of dilute acids upon casein when no soluble compounds are formed; II, The hydrolyses of the sodium salts of casein, N. Y. (Geneva) Exp. Sta. Tech. Bul. 3, pages 75-162, 1906.