Juvenile of Falco Peregrinus Macropus
The first 6 days have been the most important part of the development. The blueprint of the peregrine falcon as it is written in the genes has to be executed to the smallest detail. One little mistake means the death of the embryo.
At the end of day 5 all organs needed to stay alive after hatching are there, very small, but they are there. In the next embryonic period the organs have to grow and develop into the very specialised functions they have to provide.
From day 6 the development of the sexual organs start. Embryonic cells destined to someday become eggs or sperm are called primordial germ cells. Primordial germ cells first become recognizable in the yolk sac of the embryo. If the chick embryo is genetically female, these germ cells will migrate from the yolk sac through the mesentery to the body cavity of the embryo and develop into an ovary. The ovaries can be seen around day eight in the female chick embryo. The embryonic ovary is made up of germ cells which have multiplied to form clusters. Only one cell within a cluster will actually become an egg, destined to undergo meiosis and carry on the gene pool. This cell is called an oocyte. The remaining cells will become specialized to protect and nuture the developing oocyte. The oocyte and its surrounding cluster of specialized cells are called an ovarian follicle.
Om Day 10:
The bones of the legs begin to form.
The crop begins to form.
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.
The amnion has a regual beat
There is an activ transport of amino acids in the yolksac.
