1. A guide to what is happening each of the 21 days inside the egg
A guide to what is happening each of the 21 days inside the egg. A great resource for students!

2. The appearance of the vertebral column occurs.
The nervous system begins to develop.
The head starts to form.
The eyes are beginning to develop.

3. The heart forms on day two.
The ears form on this day.
The heart begins beating after the first forty two hours of development.

4. The nose begins to form.
The wings begin to develop on this day.
The legs have started to form.

5. The tongue begins to form on this day.

6. The reproductive system begins to form.
It is now possible to determine the gender (male or female) of the baby chick.

7. The beak of the baby chick begins to form on this day.
The egg tooth begins to form as well.

8. The beak continues to form.
The baby chick now weighs more than half a gram.

9. The feathers of the baby chick begin to form.
The baby weighs over a gram now. 9

10. The feathers continue to form.
When candled, some parts of the chick can be identified.

11. The beak begins the hardening process.

12. The legs continue to grow.
The wings also continue to extend and grow.

13. The legs are fully developed at this time.
By this day the chick looks like a chick, but needs to grow in size to fill the egg.

14. The scales and claws appear on this day.
The legs are fully formed now.

15. The baby chick gets into a suitable position for breaking the shell and hatching.

16. The baby chick is gaining weight and strength every day.

17. The scales, claws and beak have become firm and horny in texture.

18. The beak of the baby chick now turns toward the air cell.
The beak pierces the membrane so it can breathe using the air cell.

19. The baby chick can be heard cheeping inside the egg now that the beak is in the air cell.

20. The yolk sac begins to be absorbed into the chick’s body cavity.
The chicks can communicate with one another and their mother now.

21. The yolk sac is now completely drawn into the chick’s body cavity.
The baby chick occupies all of the space inside the egg except the air cell.

22. The fully formed baby chick hatches!