Turning and Candling Eggs

We have been studying the life cycle of a chick all month and we are now about halfway to the hatch! Everyday two students are our "official egg turners," turning the eggs in the incubator to help ensure proper embryo development inside the eggs. At the end of last week we candled the eggs so we could have a look at what's happening inside them!

To candle the eggs we turn out the lights in the room and shine a bright light through the eggs one at a time (parents you will will recognize the overhead projector that I have saved for this sole purpose -- the kids see it as an "egg candling machine"). We have the egg sitting on a piece of cardboard with a hole in it to concentrate the light and rotate the egg slowly to look inside. In the photos below you are able to see a round glowing spot at the end of the egg which is the air space. The day before hatching the chick will peck through the membrane inside the shell and take its first breath from this space! In the next few hours it begins to hatch. You may also be able to tell in the photos that there is an area of the egg that is clearer (the egg white/albumen) and a darker area (where the embryo is). In some of the eggs we were even able to see blood vessels and an even darker spot which is the embryo's eye! These don't show up in our photographs.

Stay tuned for more as we get closer to the hatch!