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• DAY 1: Appearance of embryonic tissue.
  • 16 hours—first sign of resemblance to a chick embryo
  • 18 hours—appearance of alimentary tract
  • 20 hours—appearance of vertebral column
  • 21 hours—beginning of nervous system
  • 22 hours—beginning of head
  • 24 hours—beginning of eye
• DAY 2: Tissue development very visible. Appearance of blood vessels.
  • 25 hours—beginning of heart
  • 35 hours—beginning of ear
  • 42 hours—heart beats
• DAY 3: Heart beats. Blood vessels very visible.
  • 60 hours—beginning of nose
  • 62 hours—beginning of legs
  • 64 hours—beginning of wings
• DAY 4: Eye pigmented.
  • beginning of tongue
• DAY 5: Appearance of elbows and knees.
  • formation of reproductive organs and differentiation of sex
• DAY 6: Appearance of beak. Voluntary movements begin.
• DAY 7: Comb growth begins. Egg tooth begins to appear.
• DAY 8: Feather tracts seen. Upper and lower beak equal in length.
• DAY 9: Embryo starts to look bird-like. Mouth opening occurs.
• DAY 10: Egg tooth prominent. Toe nails visible.
• DAY 11: Cob serrated. Tail feathers apparent.
• DAY 12: Toes fully formed. First few visible feathers.
• DAY 13: Appearance of scales. Body covered lightly with feathers.
• DAY 14: Embryo turns head towards large end of egg.
• DAY 15: Gut is drawn into abdominal cavity.
• DAY 16: Feathers cover complete body. Albumen nearly gone.
• DAY 17: Amniotic fluid decreases. Head is between legs.
• DAY 18: Growth of embryo nearly complete. Yolk sac remains outside of embryo. Head is under right wing.