Chicken Egg Development Taken and edited from Matt Patton’s CTEOnline lesson chicken embryo development

Day 1 18 hours: The alimentary tract appears. 19 hours: The brain crease begins to form. 20 hours: Somites appear. 21 hours: The brain and nervous system begin to form. 22 hours: The head fold begins to form. 23 hours: Blood islands appear. 24 hours: The eyes begin to form. Explain the process of how it works and what the machine does

Day 2 25 hours: The heart begins to form. 33 hours: The ears begin to form. 42 hours: The heart starts to beat. Explain the process of how it works and what the machine does

Day 3 The head begins to turn onto its left side. The tongue begins to form. The amnion completely surrounds the embryo. The tail has appeared. Wing and leg buds are visible. Soon other organs such as the liver, kidneys, and lungs will appear. Explain the process of how it works and what the machine does

Eye Pigmented The toes begin to form. Day 4 Explain the process of how it works and what the machine does

Day 5 The reproductive organs begin to form. The bones of the legs begin to form. The crop begins to form. Explain the process of how it works and what the machine does

Day 6 The beak becomes visible. The wing bends at the elbow. The allantois begins to fuse with the chorion. The ribs begin to appear. The gizzard begins to form. The intestines begin to loop.

Day 7 A row of feather germs appears on the tail. The sclera of the eye begins to form. Feather papillae appear on the thigh. The leg bends at the knee.

Day 8 Three rows of feather germs are visible on the tail. The nictitating membranes (inner eye lids) begins to form. The egg tooth begins to form. The bone marrow cavity of the femur begins to form. Explain the process of how it works and what the machine does

Day 9 Upper eye lids begin to cover the eyes. The knee caps begin to form. Explain the process of how it works and what the machine does

Day 10 Claws begin to form. The comb is visible. Flight feathers appear. Feather tracts appear over the sternum. Lower eyelids develop. Explain the process of how it works and what the machine does

Day 11 The toe claws begin to curve downward. The bottom of the feet become padded. Feather germs on the back and tail appear as long, tapering cones. The beak begins to harden. The comb appears serrated. The embryo begins to draw calcium from the eggshell for its growing bones. Explain the process of how it works and what the machine does

Day 12 Scales appear on the lower legs. The embryo continues to grow and move. The ribs begin to ossify.

Fingers of the wings are covered with feather papillae. Day 13 Fingers of the wings are covered with feather papillae. The left and right collar bones fuse to form the wishbone. Explain the process of how it works and what the machine does

Day 14 The embryo turns its head toward the blunt end of the egg. The skull has begun to ossify. Explain the process of how it works and what the machine does

The scales, claws, and beak are becoming firm. Day 15 The scales, claws, and beak are becoming firm. Explain the process of how it works and what the machine does

Day 16 The embryo turns its beak toward the air cell. The chorioallantoic cavity lines most of the inside surface of the egg shell.

The beak turns towards the air cell. Day 17 The beak turns towards the air cell. Explain the process of how it works and what the machine does

Growth of embryo nearly complete Yolk sac is still outside the embryo Day 18 Growth of embryo nearly complete Yolk sac is still outside the embryo Head is under right wing Explain the process of how it works and what the machine does

Day 19 Yolk sac draws into the body cavity Amniotic fluid gone Embryo occupies most of the space within the egg (not in the air cell)

Day 20 Yolk sac completely drawn into body cavity. Embryo becomes a chick (breathing in air cell) Internal and External pip Explain the process of how it works and what the machine does

Day 21 HATCHES Explain the process of how it works and what the machine does