Science Questions

How can an egg be inside another egg?

I cracked open a large chicken egg this morning and out came the white, an egg yolk, and another fully-formed shelled egg. Any thoughts on why this happened? Leslie via email

I've never heard of that happen before. The reason that's bizarre is because when an egg forms, the chicken makes the egg and puts the shell around it as it descends along the oviduct of the chicken. So for that to have happened, it suggests that an egg must have formed, or misformed, and then got engulfed by another egg that was forming once it had already partially formed. It's a bit like cases where ladies have given birth to babies and they've found the remains of a dead twin inside the body of the surviving baby.

October 2006