Developing Egg

We have a broody hen who we have been allowing to set on 12 eggs.  She is in a corner of the hay shed and very protective of her eggs.  We marked the 12 eggs that we would allow to stay and just gather any extras from the nest once a day.  Today when I went to collect, I found that one of the marked eggs had rolled out of the nest and was stone cold.  I brought it in, knowing that the chick couldn't survive being that cold.  We opened it up for a little science lesson (being homeschoolers, we grab every opportunity).  It was less developed than I thought.  The yolk was completely runny (yolk is absorbed by chick for nourishment) and there was a bit of blood.  The kids didn't think there was anything there, but at closer inspection I found the baby chick, we could see it's eye and little heart slowly beating and then becoming still.  Wow!  From this website, it appears that the chick was about 2-5 days developed.  Amazing little life!  How sad.  Let's hope the next 11 survive.  I put some extra padding around the nest to prevent any others from rolling out, hopefully that will work.

Here are a couple pictures:

More learning and info, including some worksheets for kids is located here.

Here is a YouTube video showing all 3 weeks of development.