| The egg is now filled with an embryo. The only space left in the egg is the air sac. The embryo becomes a chicken. This happens when it starts actually breathing the air in the air sac. | | |
| Many important parts begin to develop. For example, nervous system with beginning of brain and spine start to develop. Also, the head start to form. The blood starts to flow and eyes begin to form. | | |
| Yolk of the egg starts to have blood vessels that feed the embryo. This also means that circulatory system is starting to form parts like heart and blood vessels. We can hear the heart beat. Ears and brain also are developing. | | |
| The embryo looks more and more like a real chciken, and first real feathers appear. The beak becomes hard. Embryo now has toes and skin. | | |
| Today is the day! | | |
| One of the most importand things that happens during these days is that the chicken embryo actually starts to control movement. Thios means that it can move feet or wings on purpose. During these days the beak and the feathers start to form, and embryo starts to look more like the chicken. | | |
| The embryo gets all of its feathers. The beak and claws become really hard. Also, the embryo fills almost the whole egg and starts to get ready to come out. | | |
| the embryo gets surrounded by amnionic fluid. This fluid is just like in human baby - it feeds and protects the embryo. The tiny embryo is also changing and wings and legs are beginning to grow. | | |
| During these days gizzard and tongue are formed. We can also find out if the chicken is a girl or a boy because they start to develop reproductive system. One important event that happens during these two days is that the yolk of the egg and the embryo get totally separated. | | |
| The development continues and the body has more and more feathers. Also, claws, scales and beak continue to get harder. An important thing that happens during these days is that the small intestine develops. | | |
