English: Amphibian Egg:

1. Jelly Capsule 2. Vitelline Membrane 3. Perivitelline Fluid 4. Yolk Plug 5. Embryo

The jelly capsule is designed to protect the embryo from the outside environment. This capsule also prevents the egg from drying out. The vitelline membrane is a membrane surrounding the egg. Upon fertilization, this membrane splits off from the surface of the egg and the space between the vitelline membrane and the embryo is filled with perivitelline fluid. This fluid surrounds the embryo and yolk plug. The yolk Plug nourishes the embryo and indicates that the embryo is near the end of gastrulation.