Formation of the egg
Reproductive organs of the hen
The egg is formed gradually over a period of about 25 hours. Many organs and systems help to convert raw materials from the food eaten by the hen into the various substances that become part of the egg.
The ovary
The hen, unlike most animals, has only one functional ovary - the left one - situated in the body cavity near the backbone. At the time of hatching, the female chick has up to 4000 tiny ova (reproductive cells), from some of which full-sized yolks may develop when the hen matures. Each yolk (ovum) is enclosed in a thin-walled sac, or follicle, attached to the ovary. This sac is richly supplied with blood.
The oviduct
The mature yolk is released when the sac ruptures, and is received by the funnel of the left oviduct (the right oviduct is not functional). The left oviduct is a coiled or folded tube about 80 cm in length.
Eggs come from cows.
It's a question that has always fascinated ne because the structure of an eggs seems to be far more complicated thrn that of an embryo
