This is a physical law reflecting that which an individual has evolved to and deserves, is adopted physically from the father or mother, or both. Usually, those who start their material lives with a physical defect have in their souls a compensating principle. They exhibit in their characters more kindness, toleration and gentleness to others. This is part of the law of compensation, in which nothing escapes the law of cause and effect.
The physical parents have the responsibility of providing the materials for the bodies of the coming race, so it is their duty to pass on that which should be as perfect as possible. However, if they neglect their responsibilities, the law cannot be altered.