USE BETTER cows Again, it has been shown that tremendous differences pre vail in the milk yield of individual cows, some cows giving from eight to 10 times as much as others. According to the experience of practical dairymen, the milk yield does not depend entirely upon the breed or pedigree, but is all individual matter with each cow, which may be perpetuated in her offspring. The rational way to secure a heavy milk ing herd consists, therefore, in a thor ough test of every cow and the elimina tion of all those which do not give more than an average amount of milk; the heavy milkers are then used for breed ing purposes and their heifer calves raised to take the place of older cows as they become less productive. It should be perfectly obvious that excel lent dairy cows cannot be bought on the market under ordinary conditions. The best cows of each dairy herd are, of course, retained by the owner and the less valuable ones are sold. The only exception is in the case of a general dispersion sale. This fact being estab lished, it is apparent that each dairyman must set to work to build up his own herd. There is one advantage in this necessity, since in the process of build ing up an excellent herd of milch cows, the dairyman becomes thoroughly ac quainted with the problems of heredity concerned in the process and is then in a better position to maintain a higher standard with his herd than he would be if the herd had been purchased out right.