SPECULATIONS 141 



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 inter- 

 fere with milking capacity as such alone. The 

 cow's size, age, and health might be mentioned, 

 for instance. If these other factors can be elimi- 

 nated, 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, 



