As one note of music can be fully audible at a time so one line of offshoots can be intelligible at a time, and it is the warmth of interest that keeps the blood running in that particular line. There may be other lines where the blood is alive also; still if they are not kept warm by one's interest they become congested and thus paralyzed; and yet the blood is there, the life is there, it awaits the moment to awaken. The sorrows of the past, the fears of the past, the joys of the past, can be brought to life after ages, and could give exactly the same sensation that one had experienced formerly.