The document summarizes the development of an organism called Concretia over 11 days from the early embryonic stage to the formation of major organ systems. Some key developments include: - By day 3, Concretia has developed a heartbeat of around 59 beats per minute. - On day 8, the swim bladder and eyes are visible and the heartbeat has increased to 148 beats per minute. - By day 10, the spleen has developed and the mouth is visible from above as the head straightens out.