of the milk is not materially enhanced. It may be of importance in inhibiting growth in the udder.

Rejection of fore-milk. The fact that the fore-milk contains per cubic centimeter so much more germ life than the remainder of the milk has led some to advocate its rejection when a sanitary milk supply is under consideration. While from a purely quantitative point of view, this custom may be considered advantageous, in practice, however, it is hardly worth while since it is not at all certain that the rejection will have any effect on the keeping quality or healthfulness of milk. This is especially true if the ends of the teats are thoroughly cleaned before milking. It is true that the fore-milk is relatively deficient in fat so that the loss of butter fat occasioned by the rejection of the first few streams is comparatively slight.

Contamination from utensils. One of the most important phases of contamination is that which comes from the utensils used to hold the milk from the time it is drawn until it is utilized. Not only is this important because it is a leading factor in the infection of milk, but because much improvement can be secured with but little trouble, and it is especially necessary that the dairy student should be made familiar with the various conditions that obtain. Pails and cans used to hold milk may be apparently clean to the eye, and yet contribute materially to the germ content of the milk placed in them. Not only does much depend upon their condition, but it is equally important to take into consideration their manner of construction. Dairy utensils should be simple in construction, rather than complex. They should be made so that they can be readily and easily cleaned, or otherwise the cleaning process is apt to be neglected.

Of first importance are those utensils that are used to collect the milk and in which it is handled while on the farm. The warm milk is first received in pails, and unless these are scrupulously cleaned, an important initial contamination then occurs. As ordinarily washed, the process falls far short of ridding the utensils of the bacterial life that is adherent to the inner surface of the pail. Then, too, all angles or crevices afford an excellent hiding place for bacteria, and it is very important to see that all seams are well soldered. Round corners and angles flushed with solder greatly facilitate thorough cleaning of utensils. Tin utensils are recognized as most satisfactory.

Shipping cans are likely to serve as greater infecting agents than pails for they are subject to more wear and tear and are harder to clean. As long as the surface is bright and smooth, it may be easily cleaned, but large utensils, such as cans, are likely to become dented and rusty in spots on the inner side. The storage of milk in such utensils results in its rapid deterioration. The action of rennet has been found to be greatly retarded where milk comes in contact with a rusty iron surface. It is also probable that some of the abnormal flavors in butter are due to the action of acid cream on iron or copper surfaces from which the tin has been worn. It is equally important that attention be paid to the care of strainers, coolers, and the small utensils. Cloth strainers are more or less of a hotbed for bacterial growth, for unless they are boiled, and then dried quickly and thoroughly, germ growth will continue apace in them, as long as they contain any moisture.

Milking machines and farm separators. The introduction of these special types of dairy machinery in the handling of milk on the farm has materially complicated the question of the care of milk. Both of these types of apparatus are much more complicated than the usual milk utensil; consequently, the danger of imperfect cleaning is thereby increased. This is still further accentuated by the fact that cleansing of utensils on the farm can never be done so well as at the factory or milk depot where steam is available. The milking machine may be easily kept in a comparatively germ-free condition, but unless this is done, it contributes its quota of germ life to the milk.

The farm separator is more widely used than the milking machine and in actual practice the grossest carelessness prevails in the matter of its care. Frequently it is not taken apart and thoroughly cleansed, but is rinsed out by passing water through the machine. It is impossible by such a treatment to remove the slime that collects on the wall of the bowl; the machine remains moist and bacterial growth can go on. Such a machine represents a most important source of contamination of milk and cream and it is probable that the widespread introduction of the hand separator has contributed more to lower the quality of cream delivered at the factory than any other single factor.

Contamination from factory by-products. The custom of returning factory by-products in the same set of cans that is used to bring fresh milk is a prominent cause of bad milk. Whey and skim milk are rich in bacterial life, and not infrequently are so handled as to become a foul, fermenting mass. If the cans used to transport this material are not scrupulously cleaned on the farm, transfer of harmful bacteria to the milk is made possible. In this way the carelessness of a single patron may be the means of seeding the whole factory supply. This custom is not only liable to produce a poor quality of milk, but it is more or less of a menace to all the patrons of a factory, inasmuch as the opportunity always obtains that disease-producing organisms may thus be introduced into the supply. Not infrequently is tuberculosis thus spread through the medium of factory by-products.