This is an Eastern Bluebird embryo, the egg probably laid 6-7 days (my guess) before incubation stopped. The egg fell from the nest box when I opened it today to check the nest. The egg was wedged between the nest and the nest-box door. The other four birds in the clutch had hatched. The egg cracked when it hit the ground. I peeled a portion of the shell away for this photo, then discarded the egg. The yolk sac, bright yellow at upper right, supplies nourishment to the developing chick.
