how to lay an egg

I’ve always wondered how a hen manages to lay an egg. improbable research links to an interesting article where the process is explained. but the article does not explain how the egg is actually “generated” in the hen itself. and the most important question is, do all eggs contain a potential biddy? e.g. could you breed the eggs you buy in the shop or not? do you know the answer? then please post a comment, and i can delete that question from my list of unanswered ones…

[via improbable]