I would not omit to mention also the law of Atavism, in this discussion of heredity. This is that expression of the law in the omission of one generation in the transmission of a quality. We sometimes see the peculiarities or defects of a man or woman not manifested in their children, but reappearing in their grandchildren.
Not long ago I was in a family where both parents and all the children had dark hair but one, and she had long, bright auburn ringlets. I asked, "Where did you get your hair?"
"From my red-headed grandmother," she answered, with a laugh, indicating that the matter had been so often discussed in her hearing that she understood it quite fully.
To cover the whole scope of the law of heredity would take more time than we have to spare. You can follow out the line of thought, and make practical application of the facts and principles here laid down.