In those early times the recollection of ancestral experiences was inherited, and, along with this, good or evil tendencies. In the blood of the descendants were to be traced the effects of the ancestors' tendencies. But, when the blood was mixed through exogamy, this close connection with ancestors was severed, and man began to live his own personal life. He began to regulate his moral tendencies according to what he experienced in his own personal life. Thus, in an unmixed blood is expressed the power of the ancestral life, and in a mixed blood the power of personal experience.... -Steiner, Occult Properties of Blood
At such times of suppressed consciousness he senses his ancestors within him, even as during his waking consciousness he senses the pictures of the outer world; that is to say, his forbears are active in his blood, and at such a time he dimly takes part in their remote life.... Everything, therefore, of which he has been the recipient as the result of sense-experience, lives and is active in his blood; his memory is stored with these experiences of his senses. Yet, on the other hand, the man of to-day is no longer conscious of what he possesses in his inward bodily life by inheritance from his ancestors. He knows naught concerning the forms of his inner organs; but in earlier times this was otherwise....
Such a man sensed what was within him, and as this inner experience was the result of heredity, he passed through the experiences of his ancestors by means of his inner faculty. He remembered not only his own childhood, but also the experiences of his ancestors. This life of his ancestors was, in fact, ever present in the pictures which his blood received, for, incredible as it may seem to the materialistic ideas of the present day, there was at one time a form of consciousness by means of which men considered not only their own sense-perceptions as their own experiences, but also the experiences of their forefathers... --Rudolph Steiner, Occult Properties of Blood