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 be gathered. And, when this happens, things that now come and go in the most mysterious manner will be under the cattle - breeder's control.

Perhaps the best way to make the possible power of Mendelism clearer is to consider what signs ought to be looked for in reference to a matter of some considerable importance, namely, milking capacity. This capacity varies enormously, a fact which in itself suggests a Mendelian phenomenon. Some bulls have a reputation for leaving good milking, others for leaving poor milking, stock: another circumstance pointing to the same conclusion. If milking capacity be a Mendelian phenomenon, then the way in which it will show itself will depend upon whether the hybrids between high and low milkers are intermediates or masqueraders. It must be remembered that other factors interfere with milking capacity as such alone. The cow's size, age, and health might be mentioned, for instance. If these other factors can be eliminated, then, if the hybrids are intermediates, there will be three grades of cows, viz. high grade, medium, and low grade. The cows' grade being manifest by their yield of milk, the difficult part of the problem is to determine the grade of the bull; and for this there is only one test, the test of breeding. He is either high grade, middle, or low grade. The following,