The part labeled I and II are parts of the female reproductive system of birds.
The infundibulum is part I and it is the initial portion of the oviduct where the egg is fertilized. It catches the egg from the ovary and provides the sperm with a place to fertilize the egg.
The magnum is part II and it is the region of the oviduct where the egg white or albumen is added around the fertilized yolk. This is where the majority of the egg white is added, providing the egg with protein.
So, together, the infundibulum and magnum are responsible for fertilization and the addition of the egg white, respectively, in the production of a bird's egg.